Fix graphics memory leak when keyboard recreated

java/src/org/futo/inputmethod/keyboard/KeyboardView.java

@@ -291,6 +291,8 @@ public class KeyboardView extends View {
     }
 
     private void freeOffscreenBuffer() {
+        setLayerType(LAYER_TYPE_NONE, null);
+
         mOffscreenCanvas.setBitmap(null);
         mOffscreenCanvas.setMatrix(null);
         if (mOffscreenBuffer != null) {

java/src/org/futo/inputmethod/keyboard/internal/DrawingPreviewPlacerView.java

@@ -61,6 +61,8 @@ public final class DrawingPreviewPlacerView extends RelativeLayout {
     }
 
     public void deallocateMemory() {
+        setLayerType(LAYER_TYPE_NONE, null);
+
         final int count = mPreviews.size();
         for (int i = 0; i < count; i++) {
             mPreviews.get(i).onDeallocateMemory();

java/src/org/futo/inputmethod/latin/InputView.java

@@ -221,4 +221,8 @@ public final class InputView extends FrameLayout {
             return false;
         }
     }
+
+    public void deallocateMemory() {
+        mMainKeyboardView.deallocateMemory();
+    }
 }

java/src/org/futo/inputmethod/latin/LatinIME.kt

@@ -126,7 +126,6 @@ class LatinIME : InputMethodService(), LifecycleOwner, ViewModelStoreOwner, Save
 
     private var lastEditorInfo: EditorInfo? = null
 
-    // TODO: Calling this repeatedly as the theme changes tends to slow everything to a crawl
     private fun recreateKeyboard() {
         latinIMELegacy.updateTheme()
         latinIMELegacy.mKeyboardSwitcher.mState.onLoadKeyboard(latinIMELegacy.currentAutoCapsState, latinIMELegacy.currentRecapitalizeState);
@@ -327,7 +326,11 @@ class LatinIME : InputMethodService(), LifecycleOwner, ViewModelStoreOwner, Save
         key(legacyInputView) {
             AndroidView(factory = {
                 legacyInputView!!
-            }, modifier = modifier)
+            }, modifier = modifier, onRelease = {
+                val view = it as InputView
+                view.deallocateMemory()
+                view.removeAllViews()
+            })
         }
     }