Merge pull request #955 from matrix-org/fix/android-composition-issues-with-compose

Android: fix composition issues with Compose

Author: jmartinesp

platforms/android/library/src/main/java/io/element/android/wysiwyg/EditorEditText.kt

@@ -14,6 +14,7 @@ import android.text.TextWatcher
 import android.util.AttributeSet
 import android.view.KeyEvent
 import android.view.MotionEvent
+import android.view.inputmethod.BaseInputConnection
 import android.view.inputmethod.EditorInfo
 import android.view.inputmethod.InputConnection
 import android.widget.EditText
@@ -77,8 +78,6 @@ class EditorEditText : AppCompatEditText {
         set(value) {
             field = value
             viewModel.htmlConverter = value
-
-            rerender()
         }
 
     private fun createHtmlConverter(styleConfig: StyleConfig, mentionDisplayHandler: MentionDisplayHandler?): HtmlConverter {
@@ -282,13 +281,23 @@ class EditorEditText : AppCompatEditText {
      * @param mentionDisplayHandler Used to decide how to display any mentions found in the HTML text.
      */
     fun updateStyle(styleConfig: StyleConfig, mentionDisplayHandler: MentionDisplayHandler?) {
-        this.styleConfig = styleConfig
-        this.mentionDisplayHandler = mentionDisplayHandler
+        var forceNewRendering = false
+        val hasNewStyle = !this::styleConfig.isInitialized || this.styleConfig != styleConfig
+        val hasNewMentionDisplayHandler = (this.mentionDisplayHandler as? MemoizingMentionDisplayHandler)
+            ?.delegateEquals(mentionDisplayHandler) != true
+        if (hasNewStyle || hasNewMentionDisplayHandler) {
+            this.styleConfig = styleConfig
+            this.mentionDisplayHandler = mentionDisplayHandler
+            forceNewRendering = true
+        }
 
         inlineCodeBgHelper = SpanBackgroundHelperFactory.createInlineCodeBackgroundHelper(styleConfig.inlineCode)
         codeBlockBgHelper = SpanBackgroundHelperFactory.createCodeBlockBackgroundHelper(styleConfig.codeBlock)
 
         htmlConverter = createHtmlConverter(styleConfig, mentionDisplayHandler)
+        if (forceNewRendering) {
+            rerender()
+        }
     }
 
     fun setOnRichContentSelected(onRichContentSelected: ((Uri) -> Unit)?) {
@@ -600,8 +609,14 @@ class EditorEditText : AppCompatEditText {
      * will be updated to reflect this.
      */
     private fun rerender() {
+        val compositionStart = BaseInputConnection.getComposingSpanStart(editableText)
+        val compositionEnd = BaseInputConnection.getComposingSpanEnd(editableText)
         val text = viewModel.rerender()
         setTextFromComposerUpdate(text)
+        val indices = text.indices
+        if (compositionStart in indices && compositionEnd in indices) {
+            inputConnection?.setComposingRegion(compositionStart, compositionEnd)
+        }
     }
 
     private fun setTextFromComposerUpdate(text: CharSequence) {

platforms/android/library/src/main/java/io/element/android/wysiwyg/inputhandlers/InterceptInputConnection.kt

@@ -121,11 +121,6 @@ internal class InterceptInputConnection(
     // Called when started typing
     override fun setComposingText(text: CharSequence, newCursorPosition: Int): Boolean {
         val (start, end) = getCurrentCompositionOrSelection()
-        // Some Chinese keyboards send empty text when the user is typing English characters
-        if (text.isEmpty() && Selection.getSelectionStart(editable) == Selection.getSelectionEnd(editable)) {
-            finishComposingText()
-            return false
-        }
         val result = processTextEntry(text, start, end, null)
 
         return if (result != null) {
@@ -284,13 +279,10 @@ internal class InterceptInputConnection(
         // append to the current composition with the hardware keyboard.
         finishComposingText()
 
-        return if (newChars.isDigitsOnly()) {
-            // Digits should be sent using `commitText`, as that's the default behaviour in the IME
-            commitText(newChars, 1)
-        } else {
-            // Any other printable character can be sent using `setComposingText`
-            setComposingText(newChars, 1)
-        }
+        // We previously tried to have hardware keys behave as composing text, but it's not
+        // possible, we run into issues where existing keyboards (i.e. Trime) send empty composing
+        // text and that breaks the input. So we need to use `commitText` instead.
+        return commitText(newChars, 1)
     }
 
     override fun deleteSurroundingText(beforeLength: Int, afterLength: Int): Boolean {

platforms/android/library/src/main/java/io/element/android/wysiwyg/internal/display/MemoizedLinkDisplayHandler.kt

@@ -38,4 +38,8 @@ internal class MemoizingMentionDisplayHandler(
 
         return calculated
     }
+
+    fun delegateEquals(other: MentionDisplayHandler?): Boolean {
+        return delegate == other
+    }
 }