Merge "[2/n] Avoid flicker to drop a widget that needs a config activity" into main
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index c1ebbe5..7267e63 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -1483,11 +1483,10 @@
         if (showPendingWidget) {
             launcherInfo.restoreStatus = LauncherAppWidgetInfo.FLAG_UI_NOT_READY;
             PendingAppWidgetHostView pendingAppWidgetHostView = new PendingAppWidgetHostView(
-                    this, mAppWidgetHolder, launcherInfo, appWidgetInfo);
-            pendingAppWidgetHostView.setPreviewBitmap(widgetPreviewBitmap);
+                    this, mAppWidgetHolder, launcherInfo, appWidgetInfo, widgetPreviewBitmap);
             hostView = pendingAppWidgetHostView;
         } else if (hostView instanceof PendingAppWidgetHostView) {
-            ((PendingAppWidgetHostView) hostView).setPreviewBitmap(null);
+            ((PendingAppWidgetHostView) hostView).setPreviewBitmapAndUpdateBackground(null);
             // User has selected a widget config and exited the config activity, we can trigger
             // re-inflation of PendingAppWidgetHostView to replace it with
             // LauncherAppWidgetHostView in workspace.
@@ -1822,7 +1821,9 @@
         if (isActivityStarted) {
             DragView dropView = getDragLayer().clearAnimatedView();
             if (dropView != null && dropView.containsAppWidgetHostView()) {
-                widgetPreviewBitmap = getBitmapFromView(dropView.getContentView());
+                // Extracting Bitmap from dropView instead of its content view produces the correct
+                // bitmap.
+                widgetPreviewBitmap = getBitmapFromView(dropView);
             }
         }
 
diff --git a/src/com/android/launcher3/RectUtils.kt b/src/com/android/launcher3/RectUtils.kt
new file mode 100644
index 0000000..68d2eaf
--- /dev/null
+++ b/src/com/android/launcher3/RectUtils.kt
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3
+
+import android.graphics.Rect
+
+/**
+ * Fit [this] into [targetRect] with letter boxing. After calling this method, [this] will be
+ * modified to be letter boxed.
+ *
+ * @param targetRect target [Rect] that [this] should be fitted into
+ */
+fun Rect.letterBox(targetRect: Rect) {
+    letterBox(targetRect, this)
+}
+
+/**
+ * Fit [this] into [targetRect] with letter boxing. After calling this method, [resultRect] will be
+ * modified to be letter boxed.
+ *
+ * @param targetRect target [Rect] that [this] should be fitted into
+ * @param resultRect the letter boxed [Rect]
+ */
+fun Rect.letterBox(targetRect: Rect, resultRect: Rect) {
+    val widthRatio: Float = 1f * targetRect.width() / width()
+    val heightRatio: Float = 1f * targetRect.height() / height()
+    if (widthRatio < heightRatio) {
+        val scaledHeight: Int = (widthRatio * height()).toInt()
+        val verticalPadding: Int = (targetRect.height() - scaledHeight) / 2
+        resultRect.set(
+            targetRect.left,
+            targetRect.top + verticalPadding,
+            targetRect.right,
+            targetRect.bottom - verticalPadding
+        )
+    } else {
+        val scaledWidth: Int = (heightRatio * width()).toInt()
+        val horizontalPadding: Int = (targetRect.width() - scaledWidth) / 2
+        resultRect.set(
+            targetRect.left + horizontalPadding,
+            targetRect.top,
+            targetRect.right - horizontalPadding,
+            targetRect.bottom
+        )
+    }
+}
diff --git a/src/com/android/launcher3/widget/PendingAppWidgetHostView.java b/src/com/android/launcher3/widget/PendingAppWidgetHostView.java
index 86400ba..7f9a1fc 100644
--- a/src/com/android/launcher3/widget/PendingAppWidgetHostView.java
+++ b/src/com/android/launcher3/widget/PendingAppWidgetHostView.java
@@ -53,6 +53,7 @@
 import com.android.launcher3.Launcher;
 import com.android.launcher3.LauncherAppState;
 import com.android.launcher3.R;
+import com.android.launcher3.RectUtilsKt;
 import com.android.launcher3.icons.FastBitmapDrawable;
 import com.android.launcher3.icons.IconCache.ItemInfoUpdateReceiver;
 import com.android.launcher3.model.data.ItemInfoWithIcon;
@@ -76,6 +77,10 @@
 
     private final Rect mRect = new Rect();
 
+    private final Rect mPreviewBitmapRect = new Rect();
+    private final Rect mCanvasRect = new Rect();
+    private final Rect mLetterBoxedPreviewBitmapRect = new Rect();
+
     private final LauncherWidgetHolder mWidgetHolder;
     private final LauncherAppWidgetProviderInfo mAppwidget;
     private final LauncherAppWidgetInfo mInfo;
@@ -103,9 +108,14 @@
 
     public PendingAppWidgetHostView(Context context, LauncherWidgetHolder widgetHolder,
             LauncherAppWidgetInfo info, @Nullable LauncherAppWidgetProviderInfo appWidget) {
-        this(context, widgetHolder, info, appWidget,
-                context.getResources().getText(R.string.gadget_complete_setup_text));
+        this(context, widgetHolder, info, appWidget, null);
+    }
 
+    public PendingAppWidgetHostView(Context context, LauncherWidgetHolder widgetHolder,
+            LauncherAppWidgetInfo info, @Nullable LauncherAppWidgetProviderInfo appWidget,
+            @Nullable Bitmap previewBitmap) {
+        this(context, widgetHolder, info, appWidget,
+                context.getResources().getText(R.string.gadget_complete_setup_text), previewBitmap);
         super.updateAppWidget(null);
         setOnClickListener(mActivityContext.getItemOnClickListener());
 
@@ -123,7 +133,7 @@
             Context context, LauncherWidgetHolder widgetHolder,
             int appWidgetId, @NonNull LauncherAppWidgetProviderInfo appWidget) {
         this(context, widgetHolder, new LauncherAppWidgetInfo(appWidgetId, appWidget.provider),
-                appWidget, appWidget.label);
+                appWidget, appWidget.label, null);
         getBackground().mutate().setAlpha(DEFERRED_ALPHA);
 
         mCenterDrawable = new ColorDrawable(Color.TRANSPARENT);
@@ -132,8 +142,12 @@
         mIsDeferredWidget = true;
     }
 
-    /** Set {@link Bitmap} of widget preview. */
-    public void setPreviewBitmap(@Nullable Bitmap previewBitmap) {
+    /**
+     * Set {@link Bitmap} of widget preview and update background drawable. When showing preview
+     * bitmap, we shouldn't draw background.
+     */
+    public void setPreviewBitmapAndUpdateBackground(@Nullable Bitmap previewBitmap) {
+        setBackgroundResource(previewBitmap != null ? 0 : R.drawable.pending_widget_bg);
         if (this.mPreviewBitmap == previewBitmap) {
             return;
         }
@@ -143,7 +157,8 @@
 
     private PendingAppWidgetHostView(Context context,
             LauncherWidgetHolder widgetHolder, LauncherAppWidgetInfo info,
-            LauncherAppWidgetProviderInfo appwidget, CharSequence label) {
+            LauncherAppWidgetProviderInfo appwidget, CharSequence label,
+            @Nullable Bitmap previewBitmap) {
         super(new ContextThemeWrapper(context, R.style.WidgetContainerTheme));
         mWidgetHolder = widgetHolder;
         mAppwidget = appwidget;
@@ -161,7 +176,7 @@
         mPreviewPaint = new Paint(ANTI_ALIAS_FLAG | DITHER_FLAG | FILTER_BITMAP_FLAG);
 
         setWillNotDraw(false);
-        setBackgroundResource(R.drawable.pending_widget_bg);
+        setPreviewBitmapAndUpdateBackground(previewBitmap);
     }
 
     @Override
@@ -440,7 +455,12 @@
     protected void onDraw(Canvas canvas) {
         if (mPreviewBitmap != null
                 && (mInfo.restoreStatus & LauncherAppWidgetInfo.FLAG_UI_NOT_READY) != 0) {
-            canvas.drawBitmap(mPreviewBitmap, 0, 0, mPreviewPaint);
+            mPreviewBitmapRect.set(0, 0, mPreviewBitmap.getWidth(), mPreviewBitmap.getHeight());
+            mCanvasRect.set(0, 0, getWidth(), getHeight());
+
+            RectUtilsKt.letterBox(mPreviewBitmapRect, mCanvasRect, mLetterBoxedPreviewBitmapRect);
+            canvas.drawBitmap(mPreviewBitmap, mPreviewBitmapRect, mLetterBoxedPreviewBitmapRect,
+                    mPreviewPaint);
             return;
         }
         if (mCenterDrawable == null) {
@@ -463,7 +483,6 @@
             mSetupTextLayout.draw(canvas);
             canvas.restore();
         }
-
     }
 
     /**
diff --git a/tests/src/com/android/launcher3/RectUtilsTest.kt b/tests/src/com/android/launcher3/RectUtilsTest.kt
new file mode 100644
index 0000000..f0d22eb
--- /dev/null
+++ b/tests/src/com/android/launcher3/RectUtilsTest.kt
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.launcher3
+
+import android.graphics.Rect
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.SmallTest
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@SmallTest
+@RunWith(AndroidJUnit4::class)
+class RectUtilsTest {
+
+    private val srcRect = Rect()
+    private val destRect = Rect()
+    private val letterBoxedRect = Rect()
+
+    @Test
+    fun letterBoxSelf_toSameRect_noScale() {
+        srcRect.set(0, 0, 100, 100)
+        destRect.set(0, 0, 100, 100)
+
+        srcRect.letterBox(destRect)
+
+        assertThat(srcRect).isEqualTo(Rect(0, 0, 100, 100))
+    }
+
+    @Test
+    fun letterBox_toSameRect_noScale() {
+        srcRect.set(0, 0, 100, 100)
+        destRect.set(0, 0, 100, 100)
+
+        srcRect.letterBox(destRect, letterBoxedRect)
+
+        assertThat(letterBoxedRect).isEqualTo(Rect(0, 0, 100, 100))
+        assertThat(srcRect).isEqualTo(Rect(0, 0, 100, 100))
+    }
+
+    @Test
+    fun letterBoxSelf_toSmallHeight_scaleDownHorizontally() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(0, 0, 939, 520)
+
+        srcRect.letterBox(destRect)
+
+        assertThat(srcRect).isEqualTo(Rect(114, 0, 825, 520))
+    }
+
+    @Test
+    fun letterBoxRect_toSmallHeight_scaleDownHorizontally() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(0, 0, 939, 520)
+
+        srcRect.letterBox(destRect, letterBoxedRect)
+
+        assertThat(letterBoxedRect).isEqualTo(Rect(114, 0, 825, 520))
+        assertThat(srcRect).isEqualTo(Rect(0, 0, 2893, 2114))
+    }
+
+    @Test
+    fun letterBoxSelf_toSmallHeightWithOffset_scaleDownHorizontally() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(10, 20, 949, 540)
+
+        srcRect.letterBox(destRect)
+
+        assertThat(srcRect).isEqualTo(Rect(124, 20, 835, 540))
+    }
+
+    @Test
+    fun letterBoxRect_toSmallHeightWithOffset_scaleDownHorizontally() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(10, 20, 949, 540)
+
+        srcRect.letterBox(destRect, letterBoxedRect)
+
+        assertThat(letterBoxedRect).isEqualTo(Rect(124, 20, 835, 540))
+        assertThat(srcRect).isEqualTo(Rect(0, 0, 2893, 2114))
+    }
+
+    @Test
+    fun letterBoxSelf_toSmallWidth_scaleDownVertically() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(0, 0, 520, 939)
+
+        srcRect.letterBox(destRect)
+
+        assertThat(srcRect).isEqualTo(Rect(0, 280, 520, 659))
+    }
+
+    @Test
+    fun letterBoxRect_toSmallWidth_scaleDownVertically() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(0, 0, 520, 939)
+
+        srcRect.letterBox(destRect, letterBoxedRect)
+
+        assertThat(letterBoxedRect).isEqualTo(Rect(0, 280, 520, 659))
+        assertThat(srcRect).isEqualTo(Rect(0, 0, 2893, 2114))
+    }
+
+    @Test
+    fun letterBoxSelf_toSmallWidthWithOffset_scaleDownVertically() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(40, 60, 560, 999)
+
+        srcRect.letterBox(destRect)
+
+        assertThat(srcRect).isEqualTo(Rect(40, 340, 560, 719))
+    }
+
+    @Test
+    fun letterBoxRect_toSmallWidthWithOffset_scaleDownVertically() {
+        srcRect.set(0, 0, 2893, 2114)
+        destRect.set(40, 60, 560, 999)
+
+        srcRect.letterBox(destRect, letterBoxedRect)
+
+        assertThat(letterBoxedRect).isEqualTo(Rect(40, 340, 560, 719))
+        assertThat(srcRect).isEqualTo(Rect(0, 0, 2893, 2114))
+    }
+}