Add contrast pill to workspace apps

When the flag is enabled, allow the BubbleTextView to draw a background
pill behind the app title. Also change the color of the text to properly
ensure contrast.  The contrast pill is only enabled for workpace apps,
so attempt draw the pill only for DoubleShadowBubbleTextView elements.

Bug: 341217082
Flag: com.android.launcher3.enable_contrast_tiles
Test: Manual, visual change
Change-Id: Idce27bd8dfca4b525c762fcd0873562f31b45b8f

src/com/android/launcher3/BubbleTextView.java

@@ -20,6 +20,7 @@ import static android.graphics.fonts.FontStyle.FONT_WEIGHT_BOLD;
 import static android.graphics.fonts.FontStyle.FONT_WEIGHT_NORMAL;
 import static android.text.Layout.Alignment.ALIGN_NORMAL;
 
+import static com.android.launcher3.Flags.enableContrastTiles;
 import static com.android.launcher3.Flags.enableCursorHoverStates;
 import static com.android.launcher3.graphics.PreloadIconDrawable.newPendingIcon;
 import static com.android.launcher3.icons.BitmapInfo.FLAG_NO_BADGE;
@@ -39,6 +40,7 @@ import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.Rect;
+import android.graphics.RectF;
 import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
 import android.icu.text.MessageFormat;
@@ -722,6 +724,29 @@ public class BubbleTextView extends TextView implements ItemInfoUpdateReceiver,
         }
     }
 
+    /** Draws a background behind the App Title label when required. **/
+    public void drawAppContrastTile(Canvas canvas) {
+        RectF appTitleBounds;
+        Paint.FontMetrics fm = getPaint().getFontMetrics();
+        Rect tmpRect = new Rect();
+        getDrawingRect(tmpRect);
+
+        if (mIcon == null) {
+            appTitleBounds = new RectF(0, 0, tmpRect.right,
+                    (int) Math.ceil(fm.bottom - fm.top));
+        } else {
+            Rect iconBounds = new Rect();
+            getIconBounds(iconBounds);
+            int textStart = iconBounds.bottom + getCompoundDrawablePadding();
+            appTitleBounds = new RectF(tmpRect.left, textStart, tmpRect.right,
+                    textStart + (int) Math.ceil(fm.bottom - fm.top));
+        }
+
+        canvas.drawRoundRect(appTitleBounds, appTitleBounds.height() / 2,
+                appTitleBounds.height() / 2,
+                PillColorProvider.getInstance(getContext()).getAppTitlePillPaint());
+    }
+
     /** Draws a line under the app icon if this is representing a running app in Desktop Mode. */
     protected void drawRunningAppIndicatorIfNecessary(Canvas canvas) {
         if (mRunningAppState == RunningAppState.NOT_RUNNING || mDisplay != DISPLAY_TASKBAR) {
@@ -909,7 +934,9 @@ public class BubbleTextView extends TextView implements ItemInfoUpdateReceiver,
 
     @Override
     public void setTextColor(ColorStateList colors) {
-        mTextColor = colors.getDefaultColor();
+        mTextColor = shouldDrawAppContrastTile() ? PillColorProvider.getInstance(
+                getContext()).getAppTitleTextPaint().getColor()
+                : colors.getDefaultColor();
         mTextColorStateList = colors;
         if (Float.compare(mTextAlpha, 1) == 0) {
             super.setTextColor(colors);
@@ -926,6 +953,15 @@ public class BubbleTextView extends TextView implements ItemInfoUpdateReceiver,
                 && info.container != LauncherSettings.Favorites.CONTAINER_HOTSEAT_PREDICTION);
     }
 
+    /**
+     * Whether or not an App title contrast tile should be drawn for this element.
+     **/
+    public boolean shouldDrawAppContrastTile() {
+        return mDisplay == DISPLAY_WORKSPACE && shouldTextBeVisible()
+                && PillColorProvider.getInstance(getContext()).isMatchaEnabled()
+                && enableContrastTiles();
+    }
+
     public void setTextVisibility(boolean visible) {
         setTextAlpha(visible ? 1 : 0);
     }

src/com/android/launcher3/Launcher.java

@@ -537,6 +537,7 @@ public class Launcher extends StatefulActivity<LauncherState>
 
         mPopupDataProvider = new PopupDataProvider(this::updateNotificationDots);
         mWidgetPickerDataProvider = new WidgetPickerDataProvider();
+        PillColorProvider.getInstance(mWorkspace.getContext()).registerObserver();
 
         boolean internalStateHandled = ACTIVITY_TRACKER.handleCreate(this);
         if (internalStateHandled) {
@@ -1813,6 +1814,7 @@ public class Launcher extends StatefulActivity<LauncherState>
         // changes while launcher is still loading.
         getRootView().getViewTreeObserver().removeOnPreDrawListener(mOnInitialBindListener);
         mOverlayManager.onActivityDestroyed();
+        PillColorProvider.getInstance(mWorkspace.getContext()).unregisterObserver();
     }
 
     public LauncherAccessibilityDelegate getAccessibilityDelegate() {

src/com/android/launcher3/PillColorPorovider.kt

@@ -0,0 +1,85 @@
+/*
+ * 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.content.Context
+import android.database.ContentObserver
+import android.graphics.Paint
+import android.net.Uri
+import android.provider.Settings
+import com.android.launcher3.util.Executors.ORDERED_BG_EXECUTOR
+
+class PillColorProvider private constructor(c: Context) {
+    private val context = c.applicationContext
+
+    private val matchaUri by lazy { Settings.Secure.getUriFor(MATCHA_SETTING) }
+    var appTitlePillPaint = Paint()
+        private set
+
+    var appTitleTextPaint = Paint()
+        private set
+
+    private var isMatchaEnabledInternal = 0
+
+    var isMatchaEnabled = isMatchaEnabledInternal != 0
+
+    private val pillColorObserver =
+        object : ContentObserver(ORDERED_BG_EXECUTOR.handler) {
+            override fun onChange(selfChange: Boolean, uri: Uri?) {
+                if (uri == matchaUri) {
+                    isMatchaEnabledInternal =
+                        Settings.Secure.getInt(context.contentResolver, MATCHA_SETTING, 0)
+                    isMatchaEnabled = isMatchaEnabledInternal != 0
+                }
+            }
+        }
+
+    fun registerObserver() {
+        context.contentResolver.registerContentObserver(matchaUri, false, pillColorObserver)
+        setup()
+    }
+
+    fun unregisterObserver() {
+        context.contentResolver.unregisterContentObserver(pillColorObserver)
+    }
+
+    fun setup() {
+        appTitlePillPaint.color =
+            context.resources.getColor(
+                R.color.material_color_surface_container_lowest,
+                context.theme,
+            )
+        appTitleTextPaint.color =
+            context.resources.getColor(R.color.material_color_on_surface, context.theme)
+        isMatchaEnabledInternal = Settings.Secure.getInt(context.contentResolver, MATCHA_SETTING, 0)
+        isMatchaEnabled = isMatchaEnabledInternal != 0
+    }
+
+    companion object {
+        private var INSTANCE: PillColorProvider? = null
+        private const val MATCHA_SETTING = "matcha_enable"
+
+        // TODO: Replace with a Dagger injection that is a singleton.
+        @JvmStatic
+        fun getInstance(context: Context): PillColorProvider {
+            if (INSTANCE == null) {
+                INSTANCE = PillColorProvider(context)
+            }
+            return INSTANCE!!
+        }
+    }
+}

src/com/android/launcher3/views/DoubleShadowBubbleTextView.java

@@ -102,6 +102,9 @@ public class DoubleShadowBubbleTextView extends BubbleTextView {
 
     @Override
     public void onDraw(Canvas canvas) {
+        if (shouldDrawAppContrastTile()) {
+            drawAppContrastTile(canvas);
+        }
         // If text is transparent or shadow alpha is 0, don't draw any shadow
         if (skipDoubleShadow()) {
             super.onDraw(canvas);