Make input edit text grow dynamically

app/build.gradle

@@ -194,7 +194,7 @@ android {
         versionCode canonicalVersionCode * postFixSize
         versionName canonicalVersionName
 
-        minSdkVersion 21
+        minSdkVersion 23
         targetSdkVersion 30
 
         multiDexEnabled = true

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationActivityV2.kt

@@ -64,7 +64,6 @@ class ConversationActivityV2 : PassphraseRequiredActionBarActivity() {
         threadID = intent.getLongExtra(THREAD_ID, -1)
         setUpRecyclerView()
         setUpToolBar()
-        setUpInputBar()
     }
 
     private fun setUpRecyclerView() {
@@ -97,10 +96,6 @@ class ConversationActivityV2 : PassphraseRequiredActionBarActivity() {
         profilePictureView.update(thread, threadID)
     }
 
-    private fun setUpInputBar() {
-        inputBar.inputBarEditText.imeOptions = inputBar.inputBarEditText.imeOptions or 16777216 // Always use incognito keyboard
-    }
-
     override fun onPrepareOptionsMenu(menu: Menu): Boolean {
         ConversationMenuHelper.onPrepareOptionsMenu(menu, menuInflater, thread, this) { onOptionsItemSelected(it) }
         super.onPrepareOptionsMenu(menu)

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/input_bar/InputBar.kt

@@ -5,10 +5,13 @@ import android.util.AttributeSet
 import android.view.LayoutInflater
 import android.widget.LinearLayout
 import android.widget.RelativeLayout
+import kotlinx.android.synthetic.main.activity_conversation_v2.*
 import kotlinx.android.synthetic.main.view_input_bar.view.*
 import network.loki.messenger.R
+import org.thoughtcrime.securesms.loki.utilities.toDp
+import kotlin.math.roundToInt
 
-class InputBar : LinearLayout {
+class InputBar : LinearLayout, InputBarEditTextDelegate {
 
     private val attachmentsButton by lazy { InputBarButton(context, R.drawable.ic_plus_24) }
     private val microphoneButton by lazy { InputBarButton(context, R.drawable.ic_microphone) }
@@ -34,6 +37,16 @@ class InputBar : LinearLayout {
         microphoneButtonContainer.addView(microphoneButton)
         microphoneButton.layoutParams = RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT)
         microphoneButton.setOnClickListener {  }
+        inputBarEditText.imeOptions = inputBarEditText.imeOptions or 16777216 // Always use incognito keyboard
+        inputBarEditText.delegate = this
+    }
+    // endregion
+
+    override fun inputBarEditTextHeightChanged(newValue: Int) {
+        val vMargin = resources.getDimension(R.dimen.small_spacing).roundToInt()
+        val layoutParams = this.layoutParams as RelativeLayout.LayoutParams
+        layoutParams.height = newValue + 2 * vMargin
+        this.layoutParams = layoutParams
     }
     // endregion
 }

app/src/main/java/org/thoughtcrime/securesms/conversation/v2/input_bar/InputBarEditText.kt

@@ -0,0 +1,44 @@
+package org.thoughtcrime.securesms.conversation.v2.input_bar
+
+import android.content.Context
+import android.text.Layout
+import android.text.StaticLayout
+import android.util.AttributeSet
+import android.widget.RelativeLayout
+import androidx.appcompat.widget.AppCompatEditText
+import org.thoughtcrime.securesms.loki.utilities.toPx
+import kotlin.math.max
+import kotlin.math.min
+import kotlin.math.roundToInt
+
+class InputBarEditText : AppCompatEditText {
+    var delegate: InputBarEditTextDelegate? = null
+
+    private val snMinHeight = toPx(40.0f, resources)
+    private val snMaxHeight = toPx(80.0f, resources)
+
+    constructor(context: Context) : super(context)
+    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
+    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
+
+    override fun onTextChanged(text: CharSequence, start: Int, lengthBefore: Int, lengthAfter: Int) {
+        super.onTextChanged(text, start, lengthBefore, lengthAfter)
+        val builder = StaticLayout.Builder.obtain(text, 0, text.length, paint, width)
+            .setAlignment(Layout.Alignment.ALIGN_NORMAL)
+            .setLineSpacing(0.0f, 1.0f)
+            .setIncludePad(false)
+        val layout = builder.build()
+        val height = layout.height.toFloat()
+        val constrainedHeight = min(max(height, snMinHeight), snMaxHeight)
+        if (constrainedHeight.roundToInt() == this.height) { return }
+        val layoutParams = this.layoutParams as? RelativeLayout.LayoutParams ?: return
+        layoutParams.height = constrainedHeight.roundToInt()
+        this.layoutParams = layoutParams
+        delegate?.inputBarEditTextHeightChanged(constrainedHeight.roundToInt())
+    }
+}
+
+interface InputBarEditTextDelegate {
+
+    fun inputBarEditTextHeightChanged(newValue: Int)
+}

app/src/main/res/layout/view_input_bar.xml

@@ -22,7 +22,7 @@
             android:layout_centerVertical="true"
             android:layout_marginStart="@dimen/small_spacing" />
 
-        <EditText
+        <org.thoughtcrime.securesms.conversation.v2.input_bar.InputBarEditText
             android:id="@+id/inputBarEditText"
             android:layout_width="match_parent"
             android:layout_height="40dp"