Updated on 2026-08-14

2020-09-08 15:50:55 +03:00 · 2020-09-08 15:50:55 +03:00 · 98ea9b0ead
commit 98ea9b0ead
parent 9b3f6994a9
25 changed files with 648 additions and 88 deletions
--- a/app/src/main/java/com/tangem/tap/common/CurrencyConverter.kt
+++ b/app/src/main/java/com/tangem/tap/common/CurrencyConverter.kt
@ -0,0 +1,23 @@
+package com.tangem.tap.common
+
+import com.tangem.common.extensions.isZero
+import java.math.BigDecimal
+import java.math.RoundingMode
+
+/**
+[REDACTED_AUTHOR]
+ */
+class CurrencyConverter(var rateValue: BigDecimal) {
+
+    fun toFiat(crypto: BigDecimal, decimals: Int = 2): BigDecimal {
+        return rateValue.multiply(crypto).setScale(decimals, RoundingMode.DOWN)
+    }
+
+    fun toCrypto(fiat: BigDecimal, decimals: Int): BigDecimal {
+        if (fiat.isZero() || rateValue.isZero()) return fiat
+
+        val scaledRateValue = rateValue.setScale(decimals, RoundingMode.DOWN)
+        val scaledFiat = fiat.setScale(decimals, RoundingMode.DOWN)
+        return scaledFiat.divide(scaledRateValue, RoundingMode.UP)
+    }
+}
--- a/app/src/main/java/com/tangem/tap/common/KeyboardObserver.kt
+++ b/app/src/main/java/com/tangem/tap/common/KeyboardObserver.kt
@ -0,0 +1,61 @@
+package com.tangem.tap.common
+
+import android.app.Activity
+import android.graphics.Rect
+import android.util.DisplayMetrics
+import android.view.ViewTreeObserver.OnGlobalLayoutListener
+import kotlin.math.absoluteValue
+
+class KeyboardObserver(activity: Activity) {
+
+    private val decorView = activity.window.decorView
+    private val windowManager = activity.windowManager
+    private val originalWindowHeight: Int = getWindowHeight()
+    private val onGlobalLayoutListener: OnGlobalLayoutListener = OnGlobalLayoutListener { onGlobalLayout() }
+
+    private var onKeyboardListener: ((Boolean) -> Unit)? = null
+    private var lastIsShow = false
+    private var lastWindowHeight = getWindowHeight()
+
+    fun registerListener(listener: (Boolean) -> Unit) {
+        decorView.viewTreeObserver.addOnGlobalLayoutListener(onGlobalLayoutListener)
+        onKeyboardListener = listener
+    }
+
+    fun unregisterListener() {
+        decorView.viewTreeObserver.removeOnGlobalLayoutListener(onGlobalLayoutListener)
+        onKeyboardListener = null
+    }
+
+    private fun getWindowHeight() = Rect().apply { decorView.getWindowVisibleDisplayFrame(this) }.bottom
+
+    private fun onGlobalLayout() {
+        val currentWindowHeight = getWindowHeight()
+        if (isSoftKeyChanged()) {
+            lastWindowHeight = currentWindowHeight
+            return
+        }
+
+        lastWindowHeight = currentWindowHeight
+        val isShow = originalWindowHeight != currentWindowHeight
+        if (lastIsShow == isShow) return
+
+        lastIsShow = isShow
+        onKeyboardListener?.invoke(isShow)
+    }
+
+    private fun isSoftKeyChanged() = ((lastWindowHeight - getWindowHeight()).absoluteValue) == getSoftKeyButtonHeight()
+
+    private fun getSoftKeyButtonHeight(): Int {
+        val applicationDisplayHeight = DisplayMetrics().apply {
+            windowManager.defaultDisplay.getMetrics(this)
+        }.heightPixels
+
+        val realDisplayHeight = DisplayMetrics().apply {
+            windowManager.defaultDisplay.getRealMetrics(this)
+        }.heightPixels
+
+        return realDisplayHeight - applicationDisplayHeight
+    }
+
+}
--- a/app/src/main/java/com/tangem/tap/common/entities/TapCurrency.kt
+++ b/app/src/main/java/com/tangem/tap/common/entities/TapCurrency.kt
@ -0,0 +1,10 @@
+package com.tangem.tap.common.entities
+
+/**
+[REDACTED_AUTHOR]
+ */
+class TapCurrency {
+    companion object{
+        val main = "USD"
+    }
+}
--- a/app/src/main/java/com/tangem/tap/common/extensions/Specific.kt
+++ b/app/src/main/java/com/tangem/tap/common/extensions/Specific.kt
@ -42,7 +42,7 @@ fun BigDecimal.toFormattedString(decimals: Int): String {
    df.minimumFractionDigits = 0
    df.isGroupingUsed = false
    val bd = BigDecimal(unscaledValue(), scale())
-    bd.setScale(decimals, BigDecimal.ROUND_DOWN)
+    bd.setScale(decimals, RoundingMode.DOWN)
    return df.format(bd)
 }

@ -50,4 +50,6 @@ fun BigDecimal.toFiatString(rateValue: BigDecimal): String? {
    var fiatValue = rateValue.multiply(this)
    fiatValue = fiatValue.setScale(2, RoundingMode.DOWN)
    return "≈ USD  $fiatValue"
-}
+}
+
+fun BigDecimal.stripZeroPlainString(): String = this.stripTrailingZeros().toPlainString()
--- a/app/src/main/java/com/tangem/tap/common/extensions/TextView.kt
+++ b/app/src/main/java/com/tangem/tap/common/extensions/TextView.kt
@ -0,0 +1,49 @@
+package com.tangem.tap.common.extensions
+
+import android.view.View
+import android.widget.EditText
+import android.widget.TextSwitcher
+import android.widget.TextView
+import com.google.android.material.textfield.TextInputLayout
+
+/**
+[REDACTED_AUTHOR]
+ */
+fun TextView.update(text: String?) {
+    if (this.text?.toString() != text) this.text = text
+}
+
+fun EditText.update(text: String?) {
+    if (this.text?.toString() == text) return
+
+    val textLength = text?.length ?: 0
+
+    //prevent cursor jumping while editing a text
+    val cursorPosition = if (selectionEnd > textLength) textLength else selectionEnd
+    this.setText(text)
+    if (!isFocused || textLength == 0) return
+
+    if (cursorPosition == 0) setSelection(textLength)
+    else setSelection(cursorPosition)
+}
+
+fun TextSwitcher.update(text: String?) {
+    val textView = this.currentView as? TextView ?: return
+
+    if (textView.text?.toString() != text) this.setText(text)
+}
+
+// By default the TextInputLayout didn't activates the error state if the message is empty or null
+fun TextInputLayout.enableError(enable: Boolean, errorMessage: String? = null) {
+    if (enable) {
+        if (errorMessage == null || errorMessage.isEmpty()) {
+            error = "Any message"
+            if (childCount == 2) getChildAt(1).visibility = View.GONE
+        } else {
+            error = errorMessage
+        }
+    } else {
+        error = null
+        isErrorEnabled = false
+    }
+}
--- a/app/src/main/java/com/tangem/tap/common/extensions/UI.kt
+++ b/app/src/main/java/com/tangem/tap/common/extensions/UI.kt
@ -10,7 +10,6 @@ import android.os.Build
 import android.text.Spannable
 import android.text.style.ForegroundColorSpan
 import android.util.TypedValue
-import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import android.view.inputmethod.InputMethodManager
@ -132,11 +131,4 @@ fun Context.shareText(text: String) {

 fun Fragment.shareText(text: String) {
    requireContext().shareText(text)
-}
-
-fun ViewGroup.inflate(viewToInflate: Int, rootView: ViewGroup?, parent: ViewGroup) {
-    if (rootView == null) {
-        val inflatedView = LayoutInflater.from(context).inflate(viewToInflate, rootView)
-        parent.addView(inflatedView)
-    }
 }
--- a/app/src/main/java/com/tangem/tap/common/extensions/ViewGroup.kt
+++ b/app/src/main/java/com/tangem/tap/common/extensions/ViewGroup.kt
@ -0,0 +1,21 @@
+package com.tangem.tap.common.extensions
+
+import android.view.LayoutInflater
+import android.view.ViewGroup
+import androidx.transition.AutoTransition
+import androidx.transition.Transition
+import androidx.transition.TransitionManager
+
+/**
+[REDACTED_AUTHOR]
+ */
+fun ViewGroup.inflate(viewToInflate: Int, rootView: ViewGroup?, parent: ViewGroup) {
+    if (rootView == null) {
+        val inflatedView = LayoutInflater.from(context).inflate(viewToInflate, rootView)
+        parent.addView(inflatedView)
+    }
+}
+
+fun ViewGroup.beginDelayedTransition(transition: Transition = AutoTransition()) {
+    TransitionManager.beginDelayedTransition(this, transition)
+}
--- a/app/src/main/java/com/tangem/tap/common/snackBar/MaxAmountSnackbar.kt
+++ b/app/src/main/java/com/tangem/tap/common/snackBar/MaxAmountSnackbar.kt
@ -0,0 +1,81 @@
+package com.tangem.tap.common.snackBar
+
+import android.content.Context
+import android.util.AttributeSet
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.FrameLayout
+import androidx.constraintlayout.widget.ConstraintLayout
+import androidx.coordinatorlayout.widget.CoordinatorLayout
+import com.google.android.material.snackbar.BaseTransientBottomBar
+import com.google.android.material.snackbar.ContentViewCallback
+import com.google.android.material.snackbar.Snackbar
+import com.tangem.wallet.R
+
+/**
+[REDACTED_AUTHOR]
+ */
+class MaxAmountSnackbar(
+        parent: ViewGroup,
+        content: MaxAmountSnackbarView
+) : BaseTransientBottomBar<MaxAmountSnackbar>(parent, content, content) {
+
+    companion object {
+
+        fun make(view: View, onClick: () -> Unit): MaxAmountSnackbar {
+            val parent = view.findSuitableParent() ?: throw IllegalArgumentException(
+                    "No suitable parent found from the given view. Please provide a valid view."
+            )
+            val inflater = LayoutInflater.from(view.context)
+            val customView = inflater.inflate(R.layout.view_snackbar_max_amount, parent, false) as MaxAmountSnackbarView
+            customView.setOnClickListener { onClick() }
+
+            return MaxAmountSnackbar(parent, customView).apply {
+                duration = Snackbar.LENGTH_INDEFINITE
+            }
+        }
+
+        private fun View?.findSuitableParent(): ViewGroup? {
+            var view = this
+            var fallback: ViewGroup? = null
+            do {
+                if (view is CoordinatorLayout) {
+                    return view
+                } else if (view is FrameLayout) {
+                    if (view.id == android.R.id.content) {
+                        return view
+                    } else {
+                        fallback = view
+                    }
+                }
+
+                if (view != null) {
+                    val parent = view.parent
+                    view = if (parent is View) parent else null
+                }
+            } while (view != null)
+            return fallback
+        }
+
+    }
+}
+
+class MaxAmountSnackbarView @JvmOverloads constructor(
+        context: Context,
+        attrs: AttributeSet? = null,
+        defStyleAttr: Int = 0
+) : ConstraintLayout(context, attrs, defStyleAttr), ContentViewCallback {
+
+    init {
+        View.inflate(context, R.layout.view_snackbar_max_amount_content, this)
+        clipToPadding = false
+    }
+
+
+    override fun animateContentIn(delay: Int, duration: Int) {
+    }
+
+    override fun animateContentOut(delay: Int, duration: Int) {
+    }
+}
--- a/app/src/main/java/com/tangem/tap/features/send/redux/SendMiddleware.kt
+++ b/app/src/main/java/com/tangem/tap/features/send/redux/SendMiddleware.kt
@ -7,8 +7,10 @@ import com.tangem.tap.common.redux.AppState
 import com.tangem.tap.domain.PayIdManager
 import com.tangem.tap.domain.PayIdManager.Companion.isPayId
 import com.tangem.tap.domain.isPayIdSupported
-import com.tangem.tap.features.send.redux.AddressPayIdActionUi.SetAddressOrPayId
+import com.tangem.tap.features.send.redux.AddressPayIdActionUi.ChangeAddressOrPayId
 import com.tangem.tap.features.send.redux.AddressPayIdVerifyAction.*
+import com.tangem.tap.features.send.redux.AmountActionUi.SetMainCurrency
+import com.tangem.tap.features.send.redux.AmountActionUi.ToggleMainCurrency
 import com.tangem.tap.scope
 import com.tangem.tap.store
 import kotlinx.coroutines.Dispatchers
@ -30,12 +32,23 @@ val sendMiddleware: Middleware<AppState> = { dispatch, appState ->
 }

 private fun handleSendAction(action: Action) {
-    val sendAction = action as? SendScreenActionUI ?: return
+    val sendAction = action as? SendScreenActionUi ?: return

    when (sendAction) {
        is AddressPayIdActionUi -> {
            when (sendAction) {
-                is SetAddressOrPayId -> AddressPayIdHandler().handle(sendAction.data)
+                is ChangeAddressOrPayId -> AddressPayIdHandler().handle(sendAction.data)
+            }
+        }
+        is AmountActionUi -> {
+            when (sendAction) {
+                is ToggleMainCurrency -> {
+                    if (store.state.sendState.amountState.mainCurrency.value == MainCurrencyType.FIAT) {
+                        store.dispatch(SetMainCurrency(MainCurrencyType.CRYPTO))
+                    } else {
+                        store.dispatch(SetMainCurrency(MainCurrencyType.FIAT))
+                    }
+                }
            }
        }
    }
--- a/app/src/main/java/com/tangem/tap/features/send/redux/SendReducer.kt
+++ b/app/src/main/java/com/tangem/tap/features/send/redux/SendReducer.kt
@ -1,13 +1,22 @@
 package com.tangem.tap.features.send.redux

 import android.view.View
+import com.tangem.blockchain.common.AmountType
+import com.tangem.common.extensions.isZero
+import com.tangem.tap.common.CurrencyConverter
+import com.tangem.tap.common.entities.TapCurrency
+import com.tangem.tap.common.extensions.stripZeroPlainString
 import com.tangem.tap.features.send.redux.AddressPayIdActionUi.*
 import com.tangem.tap.features.send.redux.AddressPayIdVerifyAction.AddressVerification
 import com.tangem.tap.features.send.redux.AddressPayIdVerifyAction.PayIdVerification
+import com.tangem.tap.features.send.redux.AmountActionUi.ChangeAmountToSend
+import com.tangem.tap.features.send.redux.AmountActionUi.SetMainCurrency
 import com.tangem.tap.features.send.redux.FeeActionUi.*
+import com.tangem.tap.store
 import org.rekotlin.Action
 import org.rekotlin.StateType
 import timber.log.Timber
+import java.math.BigDecimal

 /**
 [REDACTED_AUTHOR]
@ -27,12 +36,19 @@ private fun internalReduce(incomingAction: Action, sendState: SendState): SendSt
    if (incomingAction is ReleaseSendState) return SendState()
    val action = incomingAction as? SendScreenAction ?: return sendState

-    return when (action) {
+    var state = when (action) {
        is AddressPayIdActionUi -> handleAddressPayIdActionUi(action, sendState, sendState.addressPayIdState)
        is AddressPayIdVerifyAction -> handleAddressPayIdAction(action, sendState, sendState.addressPayIdState)
+        is AmountActionUi -> handleAmountActionUi(action, sendState, sendState.amountState)
        is FeeActionUi -> handleFeeActionUi(action, sendState, sendState.feeLayoutState)
        else -> sendState
    }
+    state = state.copy(sendButtonIsEnabled = state.addressPayIdState.error == null
+            && state.addressPayIdState.walletAddress?.isNotEmpty() ?: false
+            && !state.amountState.amountIsOverBalance
+            && !state.amountState.amountToSendCrypto.isZero()
+    )
+    return state
 }

 fun handleAddressPayIdActionUi(
@ -41,10 +57,10 @@ fun handleAddressPayIdActionUi(
        state: AddressPayIdState
 ): SendState {
    val result = when (action) {
-        is SetAddressOrPayId -> state
+        is ChangeAddressOrPayId -> state
        is SetTruncateHandler -> state.copy(truncateHandler = action.handler)
        is TruncateOrRestore -> {
-            if(action.truncate) state.copy(etFieldValue = state.truncatedFieldValue)
+            if (action.truncate) state.copy(etFieldValue = state.truncatedFieldValue)
            else state.copy(etFieldValue = state.normalFieldValue)
        }
    }
@ -65,6 +81,96 @@ private fun handleAddressPayIdAction(
    return updateLastState(sendState.copy(addressPayIdState = result), result)
 }

+private fun handleAmountActionUi(action: AmountActionUi, sendState: SendState, state: AmountState): SendState {
+    val rates = store.state.globalState.fiatRates
+    val wallet = store.state.walletState.wallet ?: return sendState
+    val fiatRate = rates.getRateForCryptoCurrency(wallet.blockchain.currency) ?: return sendState
+
+    val walletAmount = wallet.amounts[AmountType.Token] ?: wallet.amounts[AmountType.Coin]
+    val converter = CurrencyConverter(fiatRate)
+
+    val result = when (action) {
+        is SetMainCurrency -> {
+            when (action.mainCurrency) {
+                MainCurrencyType.FIAT -> {
+                    val fiatToSend = if (state.amountToSendCrypto.isZero()) BigDecimal.ZERO
+                    else converter.toFiat(state.amountToSendCrypto)
+
+                    val fiatBalance = converter.toFiat(walletAmount?.value ?: BigDecimal.ZERO)
+
+                    state.copy(
+                            etAmountFieldValue = fiatToSend.stripZeroPlainString(),
+                            balance = fiatBalance,
+                            mainCurrency = Value(MainCurrencyType.FIAT, TapCurrency.main),
+                            cursorAtTheSamePosition = false
+                    )
+                }
+                MainCurrencyType.CRYPTO -> {
+                    val cryptoBalance = walletAmount?.value ?: BigDecimal.ZERO
+                    state.copy(
+                            etAmountFieldValue = state.amountToSendCrypto.stripZeroPlainString(),
+                            amountToSendCrypto = state.amountToSendCrypto,
+                            balance = cryptoBalance.stripTrailingZeros(),
+                            mainCurrency = Value(MainCurrencyType.CRYPTO, walletAmount?.currencySymbol ?: "null"),
+                            cursorAtTheSamePosition = false
+                    )
+                }
+            }
+        }
+        is AmountActionUi.SetMaxAmount -> {
+            when (state.mainCurrency.value) {
+                MainCurrencyType.FIAT -> {
+                    val cryptoBalance = walletAmount?.value ?: BigDecimal.ZERO
+                    val fiatToSend = converter.toFiat(cryptoBalance)
+
+                    state.copy(
+                            etAmountFieldValue = fiatToSend.stripZeroPlainString(),
+                            amountToSendCrypto = cryptoBalance,
+                            cursorAtTheSamePosition = false
+                    )
+                }
+                MainCurrencyType.CRYPTO -> {
+                    val cryptoBalance = walletAmount?.value ?: BigDecimal.ZERO
+                    state.copy(
+                            etAmountFieldValue = cryptoBalance.stripZeroPlainString(),
+                            amountToSendCrypto = cryptoBalance,
+                            cursorAtTheSamePosition = false
+                    )
+                }
+            }
+
+        }
+        is ChangeAmountToSend -> {
+            val bdData = when {
+                action.data.isEmpty() || action.data == "0" -> BigDecimal.ZERO
+                else -> BigDecimal(action.data)
+            }
+
+            when (state.mainCurrency.value) {
+                MainCurrencyType.FIAT -> {
+                    val sendCrypto = converter.toCrypto(bdData, wallet.blockchain.decimals()).stripTrailingZeros()
+                    state.copy(
+                            etAmountFieldValue = action.data,
+                            amountToSendCrypto = sendCrypto,
+                            amountIsOverBalance = state.balance < bdData,
+                            cursorAtTheSamePosition = true
+                    )
+                }
+                MainCurrencyType.CRYPTO -> {
+                    state.copy(
+                            etAmountFieldValue = action.data,
+                            amountToSendCrypto = bdData,
+                            amountIsOverBalance = state.balance < bdData,
+                            cursorAtTheSamePosition = true
+                    )
+                }
+            }
+        }
+        else -> state
+    }
+    return updateLastState(sendState.copy(amountState = result), result)
+}
+
 private fun handleFeeActionUi(action: FeeActionUi, sendState: SendState, state: FeeLayoutState): SendState {
    val result = when (action) {
        is ToggleFeeLayoutVisibility -> {
@ -77,4 +183,4 @@ private fun handleFeeActionUi(action: FeeActionUi, sendState: SendState, state:
 }

 private fun updateLastState(sendState: SendState, lastChangedState: StateType): SendState =
-        sendState.copy(lastChangedStateType = lastChangedState)
+        sendState.copy(lastChangedStateType = lastChangedState)
--- a/app/src/main/java/com/tangem/tap/features/send/redux/SendScreenAction.kt
+++ b/app/src/main/java/com/tangem/tap/features/send/redux/SendScreenAction.kt
@ -6,19 +6,13 @@ import org.rekotlin.Action
 [REDACTED_AUTHOR]
 */
 interface SendScreenAction : Action
-interface SendScreenActionUI : SendScreenAction
+interface SendScreenActionUi : SendScreenAction

 object ReleaseSendState : Action

-sealed class FeeActionUi : SendScreenActionUI {
-    object ToggleFeeLayoutVisibility : FeeActionUi()
-    data class ChangeSelectedFee(val id: Int) : FeeActionUi()
-    class ChangeIncludeFee(val isChecked: Boolean) : FeeActionUi()
-}
-
-// shortness AddressOrPayId = APid
-sealed class AddressPayIdActionUi : SendScreenActionUI {
-    data class SetAddressOrPayId(val data: String) : AddressPayIdActionUi()
+// Address or PayId
+sealed class AddressPayIdActionUi : SendScreenActionUi {
+    data class ChangeAddressOrPayId(val data: String) : AddressPayIdActionUi()
    data class SetTruncateHandler(val handler: (String) -> String) : AddressPayIdActionUi()
    data class TruncateOrRestore(val truncate: Boolean) : AddressPayIdActionUi()
 }
@ -43,4 +37,19 @@ sealed class AddressPayIdVerifyAction : SendScreenAction {
        data class SetError(val address: String, val reason: FailReason) : AddressVerification()
        data class SetWalletAddress(val address: String) : AddressVerification()
    }
+}
+
+// Amount to send
+sealed class AmountActionUi : SendScreenActionUi {
+    object SetMaxAmount : AmountActionUi()
+    data class ChangeAmountToSend(val data: String) : AmountActionUi()
+    data class SetMainCurrency(val mainCurrency: MainCurrencyType) : AmountActionUi()
+    object ToggleMainCurrency : AmountActionUi()
+}
+
+// Fee
+sealed class FeeActionUi : SendScreenActionUi {
+    object ToggleFeeLayoutVisibility : FeeActionUi()
+    data class ChangeSelectedFee(val id: Int) : FeeActionUi()
+    class ChangeIncludeFee(val isChecked: Boolean) : FeeActionUi()
 }
--- a/app/src/main/java/com/tangem/tap/features/send/redux/SendState.kt
+++ b/app/src/main/java/com/tangem/tap/features/send/redux/SendState.kt
@ -1,18 +1,20 @@
 package com.tangem.tap.features.send.redux

 import android.view.View
-import com.tangem.blockchain.common.WalletManager
+import com.tangem.tap.common.entities.TapCurrency
 import com.tangem.wallet.R
 import org.rekotlin.StateType
+import java.math.BigDecimal

 /**
 [REDACTED_AUTHOR]
 */
 data class SendState(
-        val walletManager: WalletManager? = null,
        val lastChangedStateType: StateType = NoneState(),
        val addressPayIdState: AddressPayIdState = AddressPayIdState(),
-        val feeLayoutState: FeeLayoutState = FeeLayoutState()
+        val amountState: AmountState = AmountState(),
+        val feeLayoutState: FeeLayoutState = FeeLayoutState(),
+        val sendButtonIsEnabled: Boolean = false
 ) : StateType

 class NoneState : StateType
@ -73,6 +75,24 @@ data class AddressPayIdState(
    }
 }

+enum class MainCurrencyType {
+    FIAT, CRYPTO
+}
+
+data class Value<T>(
+        val value: T,
+        val displayedValue: String
+)
+
+data class AmountState(
+        val etAmountFieldValue: String = BigDecimal.ZERO.toPlainString(),
+        val cursorAtTheSamePosition: Boolean = true,
+        val amountToSendCrypto: BigDecimal = BigDecimal.ZERO,
+        val balance: BigDecimal = BigDecimal.ZERO,
+        val mainCurrency: Value<MainCurrencyType> = Value(MainCurrencyType.FIAT, TapCurrency.main),
+        val amountIsOverBalance: Boolean = false
+) : StateType
+
 data class FeeLayoutState(
        val visibility: Int = View.GONE,
        val selectedFeeId: Int = R.id.chipNormal,
--- a/app/src/main/java/com/tangem/tap/features/send/ui/SendFragment.kt
+++ b/app/src/main/java/com/tangem/tap/features/send/ui/SendFragment.kt
@ -1,16 +1,23 @@
 package com.tangem.tap.features.send.ui

+import android.content.Context
 import android.content.Intent
 import android.os.Bundle
 import android.view.View
 import android.widget.EditText
+import androidx.core.view.postDelayed
 import androidx.core.widget.addTextChangedListener
+import com.tangem.tap.common.KeyboardObserver
+import com.tangem.tap.common.entities.TapCurrency
 import com.tangem.tap.common.extensions.getFromClipboard
 import com.tangem.tap.common.qrCodeScan.ScanQrCodeActivity
+import com.tangem.tap.common.snackBar.MaxAmountSnackbar
 import com.tangem.tap.common.text.truncateMiddleWith
 import com.tangem.tap.features.send.BaseStoreFragment
 import com.tangem.tap.features.send.redux.AddressPayIdActionUi.*
+import com.tangem.tap.features.send.redux.AmountActionUi.*
 import com.tangem.tap.features.send.redux.FeeActionUi.*
+import com.tangem.tap.features.send.redux.MainCurrencyType
 import com.tangem.tap.features.send.redux.ReleaseSendState
 import com.tangem.tap.features.send.ui.stateSubscribers.SendStateSubscriber
 import com.tangem.tap.mainScope
@ -19,6 +26,7 @@ import com.tangem.wallet.R
 import kotlinx.android.synthetic.main.btn_paste.*
 import kotlinx.android.synthetic.main.btn_qr_code.*
 import kotlinx.android.synthetic.main.layout_send_address_payid.*
+import kotlinx.android.synthetic.main.layout_send_amount.*
 import kotlinx.android.synthetic.main.layout_send_network_fee.*
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.channels.awaitClose
@ -30,11 +38,13 @@ import kotlinx.coroutines.flow.*
 class SendFragment : BaseStoreFragment(R.layout.fragment_send) {

    private val sendSubscriber = SendStateSubscriber(this)
+    private lateinit var keyboardObserver: KeyboardObserver

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        setupAddressOrPayIdLayout()
+        setupAmountLayout()
        setupFeeLayout()
    }

@ -47,11 +57,11 @@ class SendFragment : BaseStoreFragment(R.layout.fragment_send) {
        etAddressOrPayId.inputedTextAsFlow()
                .debounce(400)
                .filter { store.state.sendState.addressPayIdState.etFieldValue != it }
-                .onEach { store.dispatch(SetAddressOrPayId(it)) }
+                .onEach { store.dispatch(ChangeAddressOrPayId(it)) }
                .launchIn(mainScope)

        imvPaste.setOnClickListener {
-            store.dispatch(SetAddressOrPayId(requireContext().getFromClipboard()?.toString() ?: ""))
+            store.dispatch(ChangeAddressOrPayId(requireContext().getFromClipboard()?.toString() ?: ""))
            store.dispatch(TruncateOrRestore(!etAddressOrPayId.isFocused))
        }
        imvQrCode.setOnClickListener {
@ -66,10 +76,57 @@ class SendFragment : BaseStoreFragment(R.layout.fragment_send) {
        if (requestCode != ScanQrCodeActivity.SCAN_QR_REQUEST_CODE) return

        val scannedCode = data?.getStringExtra(ScanQrCodeActivity.SCAN_RESULT) ?: ""
-        store.dispatch(SetAddressOrPayId(scannedCode))
+        store.dispatch(ChangeAddressOrPayId(scannedCode))
        store.dispatch(TruncateOrRestore(!etAddressOrPayId.isFocused))
    }

+    private fun setupAmountLayout() {
+        store.dispatch(SetMainCurrency(restoreMainCurrency()))
+        tvAmountCurrency.setOnClickListener { store.dispatch(ToggleMainCurrency) }
+
+        val maxAmountSnackbar = MaxAmountSnackbar.make(etAmountToSend) { store.dispatch(SetMaxAmount) }
+        var snackbarControlledByChangingFocus = false
+        keyboardObserver = KeyboardObserver(requireActivity())
+        keyboardObserver.registerListener { isShow ->
+            if (snackbarControlledByChangingFocus) return@registerListener
+
+            if (isShow) {
+                if (etAmountToSend.isFocused && !maxAmountSnackbar.isShown) maxAmountSnackbar.show()
+            } else {
+                if (maxAmountSnackbar.isShown) maxAmountSnackbar.dismiss()
+            }
+        }
+
+        etAmountToSend.setOnFocusChangeListener { v, hasFocus ->
+            snackbarControlledByChangingFocus = true
+            if (hasFocus) {
+                etAmountToSend.postDelayed(200) {
+                    maxAmountSnackbar.show()
+                    snackbarControlledByChangingFocus = false
+
+                }
+            } else {
+                etAmountToSend.postDelayed(350) {
+                    maxAmountSnackbar.dismiss()
+                    snackbarControlledByChangingFocus = false
+                }
+            }
+        }
+
+        val prevFocusChangeListener = etAmountToSend.onFocusChangeListener
+        etAmountToSend.setOnFocusChangeListener { v, hasFocus ->
+            prevFocusChangeListener.onFocusChange(v, hasFocus)
+            if (hasFocus && etAmountToSend.text?.toString() == "0") etAmountToSend.setText("")
+            if (!hasFocus && etAmountToSend.text?.toString() == "") etAmountToSend.setText("0")
+        }
+
+        etAmountToSend.inputedTextAsFlow()
+                .debounce(400)
+                .filter { store.state.sendState.amountState.etAmountFieldValue != it }
+                .onEach { store.dispatch(ChangeAmountToSend(it)) }
+                .launchIn(mainScope)
+    }
+
    private fun setupFeeLayout() {
        flExpandCollapse.setOnClickListener {
            store.dispatch(ToggleFeeLayoutVisibility)
@ -86,11 +143,24 @@ class SendFragment : BaseStoreFragment(R.layout.fragment_send) {
        store.subscribe(sendSubscriber) { appState ->
            appState.skipRepeats { oldState, newState -> oldState == newState }.select { it.sendState }
        }
-
        storeSubscribersList.add(sendSubscriber)
    }

+    fun restoreMainCurrency(): MainCurrencyType {
+        val sp = requireContext().getSharedPreferences("SendScreen", Context.MODE_PRIVATE)
+        val mainCurrency = sp.getString("mainCurrency", TapCurrency.main)
+        val foundType = MainCurrencyType.values()
+                .firstOrNull { it.name.toLowerCase() == mainCurrency!!.toLowerCase() } ?: MainCurrencyType.FIAT
+        return foundType
+    }
+
+    fun saveMainCurrency(type: MainCurrencyType) {
+        val sp = requireContext().getSharedPreferences("SendScreen", Context.MODE_PRIVATE)
+        sp.edit().putString("mainCurrency", type.name).apply()
+    }
+
    override fun onDestroy() {
+        keyboardObserver.unregisterListener()
        store.dispatch(ReleaseSendState)
        super.onDestroy()
    }
--- a/app/src/main/java/com/tangem/tap/features/send/ui/stateSubscribers/SendStateSubscriber.kt
+++ b/app/src/main/java/com/tangem/tap/features/send/ui/stateSubscribers/SendStateSubscriber.kt
@ -1,16 +1,23 @@
 package com.tangem.tap.features.send.ui.stateSubscribers

 import android.content.Context
+import android.util.TypedValue
 import android.view.ViewGroup
 import androidx.fragment.app.Fragment
-import androidx.transition.TransitionManager
+import com.tangem.tap.common.extensions.beginDelayedTransition
+import com.tangem.tap.common.extensions.enableError
+import com.tangem.tap.common.extensions.update
 import com.tangem.tap.features.send.redux.AddressPayIdState
 import com.tangem.tap.features.send.redux.AddressPayIdVerifyAction.FailReason
+import com.tangem.tap.features.send.redux.AmountState
 import com.tangem.tap.features.send.redux.FeeLayoutState
 import com.tangem.tap.features.send.redux.SendState
+import com.tangem.tap.features.send.ui.SendFragment
 import com.tangem.wallet.R
 import kotlinx.android.synthetic.main.btn_expand_collapse.*
+import kotlinx.android.synthetic.main.fragment_send.*
 import kotlinx.android.synthetic.main.layout_send_address_payid.*
+import kotlinx.android.synthetic.main.layout_send_amount.*
 import kotlinx.android.synthetic.main.layout_send_network_fee.*

 /**
@ -22,7 +29,10 @@ class SendStateSubscriber(fragment: Fragment) : FragmentStateSubscriber<SendStat
        when (state.lastChangedStateType) {
            is FeeLayoutState -> handleFeeLayoutState(fg, state.feeLayoutState)
            is AddressPayIdState -> handleAddressPayIdState(fg, state.addressPayIdState)
+            is AmountState -> handleAmountState(fg, state.amountState)
        }
+
+        fg.btnSend.isEnabled = state.sendButtonIsEnabled
    }

    private fun handleAddressPayIdState(fg: Fragment, state: AddressPayIdState) {
@ -50,16 +60,9 @@ class SendStateSubscriber(fragment: Fragment) : FragmentStateSubscriber<SendStat
        til.isHelperTextEnabled = state.isPayIdState() && parsedError == null

        // prevent cycling
-        if (state.etFieldValue == null || et.text?.toString() == state.etFieldValue) return
+        if (state.etFieldValue == null) return

-        // prevent cursor jumping while editing
-        if (et.isFocused) {
-            val prevSelection = et.selectionStart
-            et.setText(state.etFieldValue)
-            et.setSelection(prevSelection)
-        } else {
-            et.setText(state.etFieldValue)
-        }
+        et.update(state.etFieldValue)
    }

    private fun handleFeeLayoutState(fg: Fragment, layoutState: FeeLayoutState) {
@ -67,7 +70,7 @@ class SendStateSubscriber(fragment: Fragment) : FragmentStateSubscriber<SendStat
            val rotationAngle = if (fg.imvExpandCollapse.rotation == 0f) 180f else 0f
            fg.imvExpandCollapse.rotation = rotationAngle

-            (fg.llFeeContainer.parent?.parent as? ViewGroup)?.let { TransitionManager.beginDelayedTransition(it) }
+            (fg.llFeeContainer.parent?.parent as? ViewGroup)?.beginDelayedTransition()
            fg.llFeeContainer.visibility = layoutState.visibility
        }

@ -79,4 +82,33 @@ class SendStateSubscriber(fragment: Fragment) : FragmentStateSubscriber<SendStat
            fg.chipGroup.check(layoutState.selectedFeeId)
        }
    }
+
+    private fun handleAmountState(fg: Fragment, state: AmountState) {
+        fg.tilAmountToSend.enableError(state.amountIsOverBalance)
+
+        val amountToSend = state.etAmountFieldValue
+        fg.tvAmountToSendShadow.text = amountToSend
+        if (amountToSend.length > 10) {
+            // post is needed to wait for text size changes
+            fg.tvAmountToSendShadow.post {
+                fg.etAmountToSend.setTextSize(TypedValue.COMPLEX_UNIT_PX, fg.tvAmountToSendShadow.textSize - 2)
+                fg.etAmountToSend.update(amountToSend)
+                if (!state.cursorAtTheSamePosition) fg.etAmountToSend.setSelection(amountToSend.length)
+            }
+        } else {
+            val textSize = fg.resources.getDimension(R.dimen.text_size_amount_to_send)
+            fg.tvAmountToSendShadow.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize)
+            fg.etAmountToSend.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize)
+            fg.etAmountToSend.update(amountToSend)
+            if (!state.cursorAtTheSamePosition) fg.etAmountToSend.setSelection(amountToSend.length)
+        }
+
+        fg.tvAmountCurrency.update(state.mainCurrency.displayedValue)
+        (fg as? SendFragment)?.let { it.saveMainCurrency(state.mainCurrency.value) }
+
+        val balanceText = fg.getString(R.string.send_balance,
+                state.mainCurrency.displayedValue,
+                state.balance.toPlainString())
+        fg.tvBalance.update(balanceText)
+    }
 }
--- a/app/src/main/res/anim/slide_in_right.xml
+++ b/app/src/main/res/anim/slide_in_right.xml
@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+    <translate
+        android:duration="@android:integer/config_mediumAnimTime"
+        android:fromXDelta="50%p"
+        android:toXDelta="0" />
+    <alpha
+        android:duration="@android:integer/config_mediumAnimTime"
+        android:fromAlpha="0.0"
+        android:toAlpha="1.0" />
+</set>
--- a/app/src/main/res/anim/slide_out_right.xml
+++ b/app/src/main/res/anim/slide_out_right.xml
@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<set xmlns:android="http://schemas.android.com/apk/res/android">
+    <translate
+        android:duration="@android:integer/config_mediumAnimTime"
+        android:fromXDelta="0"
+        android:toXDelta="50%p" />
+    <alpha
+        android:duration="@android:integer/config_mediumAnimTime"
+        android:fromAlpha="1.0"
+        android:toAlpha="0.0" />
+</set>
--- a/app/src/main/res/layout/btn_expand_collapse.xml
+++ b/app/src/main/res/layout/btn_expand_collapse.xml
@ -11,7 +11,6 @@
    android:clickable="true"
    android:focusable="true">

-    <!-- padding was added nice ripple effect -->
    <ImageView
        android:id="@+id/imvExpandCollapse"
        android:layout_width="wrap_content"
@ -19,6 +18,7 @@
        android:layout_gravity="center"
        android:background="?selectableItemBackgroundBorderless"
        android:padding="5dp"
+        android:rotation="180"
        app:srcCompat="@drawable/ic_angle_bracket_up" />

 </FrameLayout>
--- a/app/src/main/res/layout/btn_paste.xml
+++ b/app/src/main/res/layout/btn_paste.xml
@ -10,7 +10,6 @@
    android:clickable="true"
    android:focusable="true">

-    <!-- padding was added nice ripple effect -->
    <ImageView
        android:id="@+id/imvPaste"
        android:layout_width="wrap_content"
--- a/app/src/main/res/layout/fragment_send.xml
+++ b/app/src/main/res/layout/fragment_send.xml
@ -29,7 +29,7 @@
                layout="@layout/layout_send_address_payid"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
-                android:layout_marginTop="14dp" />
+                android:layout_marginTop="16dp" />

            <include
                layout="@layout/layout_send_amount"
@ -71,11 +71,13 @@
                    android:layout_height="1dp" />

                <com.google.android.material.button.MaterialButton
+                    android:id="@+id/btnSend"
                    style="@style/TapButtonWithIcon"
                    android:layout_width="0dp"
                    android:layout_height="48dp"
                    android:layout_gravity="end"
                    android:layout_weight="1"
+                    android:enabled="false"
                    android:fontFamily="@font/saira_semi_condensed_regular"
                    android:text="@string/send_btn_send"
                    app:icon="@drawable/ic_arrow_right" />
--- a/app/src/main/res/layout/layout_send_address_payid.xml
+++ b/app/src/main/res/layout/layout_send_address_payid.xml
@ -46,7 +46,7 @@
        layout="@layout/btn_qr_code"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
-        android:layout_marginTop="16dp"
+        android:layout_marginTop="14dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="@+id/tilAddressOrPayId" />

--- a/app/src/main/res/layout/layout_send_amount.xml
+++ b/app/src/main/res/layout/layout_send_amount.xml
@ -7,40 +7,70 @@
    android:layout_height="wrap_content"
    app:layout_constraintTop_toBottomOf="@+id/tilAddressOrPayId">

-    <com.google.android.material.textfield.TextInputLayout
-        android:id="@+id/tilAmount"
+    <FrameLayout
+        android:id="@+id/flAmountToSend"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
-        android:layout_marginStart="16dp"
-        android:layout_marginEnd="16dp"
-        app:boxBackgroundColor="@android:color/transparent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

-        <com.google.android.material.textfield.TextInputEditText
-            android:id="@+id/etAmount"
+        <FrameLayout
+            android:id="@+id/flShadow"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
-            android:fontFamily="sans-serif-light"
-            android:inputType="numberDecimal"
-            android:paddingStart="0dp"
-            android:paddingEnd="96dp"
-            android:text="0"
-            android:textSize="32sp"
-            tools:text="139" />
+            android:layout_marginStart="16dp"
+            android:layout_marginEnd="16dp"
+            android:focusable="false"
+            android:visibility="invisible">

-    </com.google.android.material.textfield.TextInputLayout>
+            <TextView
+                android:id="@+id/tvAmountToSendShadow"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:focusable="false"
+                android:fontFamily="sans-serif-light"
+                android:maxLines="1"
+                android:paddingStart="0dp"
+                android:paddingEnd="96dp"
+                android:textSize="@dimen/text_size_amount_to_send"
+                app:autoSizeTextType="uniform" />
+
+        </FrameLayout>
+
+        <com.google.android.material.textfield.TextInputLayout
+            android:id="@+id/tilAmountToSend"
+            android:layout_width="match_parent"
+            android:layout_height="82dp"
+            android:layout_marginStart="16dp"
+            android:layout_marginEnd="16dp"
+            app:boxBackgroundColor="@android:color/transparent"
+            app:errorIconDrawable="@null">
+
+            <com.google.android.material.textfield.TextInputEditText
+                android:id="@+id/etAmountToSend"
+                android:layout_width="match_parent"
+                android:layout_height="82dp"
+                android:fontFamily="sans-serif-light"
+                android:inputType="numberDecimal"
+                android:paddingStart="0dp"
+                android:paddingEnd="96dp"
+                android:textSize="@dimen/text_size_amount_to_send"
+                tools:text="139" />
+
+        </com.google.android.material.textfield.TextInputLayout>
+
+    </FrameLayout>

    <TextSwitcher
-        android:id="@+id/tvCurrency"
+        android:id="@+id/tvAmountCurrency"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginBottom="12dp"
        android:inAnimation="@anim/slide_in_up"
        android:outAnimation="@anim/slide_out_down"
-        app:layout_constraintBottom_toBottomOf="@+id/tilAmount"
+        app:layout_constraintBottom_toBottomOf="@+id/flAmountToSend"
        app:layout_constraintEnd_toEndOf="parent">

        <TextView
@ -49,7 +79,6 @@
            android:layout_gravity="end"
            android:drawablePadding="10dp"
            android:fontFamily="sans-serif-light"
-            android:text="usd"
            android:textAllCaps="true"
            android:textColor="@color/blue"
            android:textSize="32sp"
@ -61,7 +90,6 @@
            android:layout_gravity="end"
            android:drawablePadding="10dp"
            android:fontFamily="sans-serif-light"
-            android:text="btc"
            android:textAllCaps="true"
            android:textColor="@color/blue"
            android:textSize="32sp"
@ -69,39 +97,29 @@

    </TextSwitcher>

-    <LinearLayout
-        android:id="@+id/balanceContainer"
+    <TextSwitcher
+        android:id="@+id/tvBalance"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="16dp"
-        android:orientation="horizontal"
+        android:inAnimation="@anim/slide_in_right"
+        android:outAnimation="@android:anim/slide_out_right"
        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintTop_toBottomOf="@+id/tilAmount">
+        app:layout_constraintTop_toBottomOf="@+id/flAmountToSend">

        <TextView
-            android:id="@+id/tvBalance"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
-            android:paddingEnd="5dp"
-            android:text="@string/send_balance"
+            android:layout_gravity="end"
            android:textColor="@color/darkGray1" />

        <TextView
-            android:id="@+id/tvBalanceCurrency"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
-            android:paddingEnd="5dp"
-            android:textColor="@color/darkGray1"
-            tools:text="USD" />
+            android:layout_gravity="end"
+            android:textColor="@color/darkGray1" />

-        <TextView
-            android:id="@+id/tvBalanceAmount"
-            android:layout_width="wrap_content"
-            android:layout_height="wrap_content"
-            android:textColor="@color/darkGray1"
-            tools:text="23.45" />
-
-    </LinearLayout>
+    </TextSwitcher>

 </androidx.constraintlayout.widget.ConstraintLayout>
--- a/app/src/main/res/layout/view_snackbar_max_amount.xml
+++ b/app/src/main/res/layout/view_snackbar_max_amount.xml
@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<com.tangem.tap.common.snackBar.MaxAmountSnackbarView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="44dp"
+    android:padding="8dp" />
--- a/app/src/main/res/layout/view_snackbar_max_amount_content.xml
+++ b/app/src/main/res/layout/view_snackbar_max_amount_content.xml
@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<merge xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:background="@color/tapButtonColorBlack"
+    tools:layout_height="44dp"
+    tools:layout_width="match_parent"
+    tools:parentTag="androidx.constraintlayout.widget.ConstraintLayout">
+
+    <androidx.appcompat.widget.AppCompatTextView
+        android:id="@+id/tv_message"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/send_set_maximum_amount"
+        android:textColor="#F4F5F6"
+        android:textSize="16sp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+</merge>
--- a/app/src/main/res/values/dimens.xml
+++ b/app/src/main/res/values/dimens.xml
@ -31,4 +31,6 @@

    <dimen name="btn_corner_radius">4dp</dimen>

+    <dimen name="text_size_amount_to_send">32sp</dimen>
+
 </resources>
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@ -58,6 +58,7 @@
    <string name="send_total_amount">Amount</string>
    <string name="send_total_fee">Fee</string>
    <string name="send_total_will_be_sent">will be sent</string>
-    <string name="send_balance">Balance:</string>
+    <string name="send_balance">Balance: %1s %2s</string>
+    <string name="send_set_maximum_amount">Maximum amount</string>

 </resources>