Add APPEARANCE_TRANSPARENT_CAPTION_BAR_BACKGROUND

To control whether the caption bar background is opaque (default) or
fully transparent. Also adds APPEARANCE_LIGHT_CAPTION_BARS to control
the foreground color of the caption bars when the background is set
to transparent and the app will draw a background themselves.

Bug: 316387515
Flag: ACONFIG android.view.flags.customizable_window_headers
DEVELOPMENT
Test: m

Change-Id: I5413ef48b1e89b624ecbbcb10bcd735c55575193

3 files changed, 39 insertions, 1 deletions

diff --git a/core/api/current.txt b/core/api/current.txt
index 4c35b4046d3e..9c270ae7bf1c 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -53746,8 +53746,10 @@ package android.view {
     method public void setSystemBarsAppearance(int, int);
     method public void setSystemBarsBehavior(int);
     method public void show(int);
+    field @FlaggedApi("android.view.flags.customizable_window_headers") public static final int APPEARANCE_LIGHT_CAPTION_BARS = 256; // 0x100
     field public static final int APPEARANCE_LIGHT_NAVIGATION_BARS = 16; // 0x10
     field public static final int APPEARANCE_LIGHT_STATUS_BARS = 8; // 0x8
+    field @FlaggedApi("android.view.flags.customizable_window_headers") public static final int APPEARANCE_TRANSPARENT_CAPTION_BAR_BACKGROUND = 128; // 0x80
     field public static final int BEHAVIOR_DEFAULT = 1; // 0x1
     field @Deprecated public static final int BEHAVIOR_SHOW_BARS_BY_SWIPE = 1; // 0x1
     field @Deprecated public static final int BEHAVIOR_SHOW_BARS_BY_TOUCH = 0; // 0x0
diff --git a/core/java/android/view/WindowInsetsController.java b/core/java/android/view/WindowInsetsController.java
index cc2cd7982841..b7542dcd55e2 100644
--- a/core/java/android/view/WindowInsetsController.java
+++ b/core/java/android/view/WindowInsetsController.java
@@ -16,6 +16,7 @@
 
 package android.view;
 
+import android.annotation.FlaggedApi;
 import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
@@ -26,6 +27,7 @@ import android.os.CancellationSignal;
 import android.view.WindowInsets.Type;
 import android.view.WindowInsets.Type.InsetsType;
 import android.view.animation.Interpolator;
+import android.view.flags.Flags;
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -78,6 +80,20 @@ public interface WindowInsetsController {
     int APPEARANCE_SEMI_TRANSPARENT_NAVIGATION_BARS = 1 << 6;
 
     /**
+     * Makes the caption bar transparent.
+     */
+    @FlaggedApi(Flags.FLAG_CUSTOMIZABLE_WINDOW_HEADERS)
+    int APPEARANCE_TRANSPARENT_CAPTION_BAR_BACKGROUND = 1 << 7;
+
+    /**
+     * When {@link WindowInsetsController#APPEARANCE_TRANSPARENT_CAPTION_BAR_BACKGROUND} is set,
+     * changes the foreground color of the caption bars so that the items on the bar can be read
+     * clearly on light backgrounds.
+     */
+    @FlaggedApi(Flags.FLAG_CUSTOMIZABLE_WINDOW_HEADERS)
+    int APPEARANCE_LIGHT_CAPTION_BARS = 1 << 8;
+
+    /**
      * Determines the appearance of system bars.
      * @hide
      */
@@ -85,7 +101,8 @@ public interface WindowInsetsController {
     @IntDef(flag = true, value = {APPEARANCE_OPAQUE_STATUS_BARS, APPEARANCE_OPAQUE_NAVIGATION_BARS,
             APPEARANCE_LOW_PROFILE_BARS, APPEARANCE_LIGHT_STATUS_BARS,
             APPEARANCE_LIGHT_NAVIGATION_BARS, APPEARANCE_SEMI_TRANSPARENT_STATUS_BARS,
-            APPEARANCE_SEMI_TRANSPARENT_NAVIGATION_BARS})
+            APPEARANCE_SEMI_TRANSPARENT_NAVIGATION_BARS,
+            APPEARANCE_TRANSPARENT_CAPTION_BAR_BACKGROUND, APPEARANCE_LIGHT_CAPTION_BARS})
     @interface Appearance {
     }
 
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/DesktopModeAppControlsWindowDecorationViewHolder.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/DesktopModeAppControlsWindowDecorationViewHolder.kt
index 144373f3550e..2309c54b6591 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/DesktopModeAppControlsWindowDecorationViewHolder.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/DesktopModeAppControlsWindowDecorationViewHolder.kt
@@ -8,6 +8,8 @@ import android.graphics.Bitmap
 import android.graphics.Color
 import android.view.View
 import android.view.View.OnLongClickListener
+import android.view.WindowInsetsController.APPEARANCE_LIGHT_CAPTION_BARS
+import android.view.WindowInsetsController.APPEARANCE_TRANSPARENT_CAPTION_BAR_BACKGROUND
 import android.widget.ImageButton
 import android.widget.ImageView
 import android.widget.TextView
@@ -79,6 +81,9 @@ internal class DesktopModeAppControlsWindowDecorationViewHolder(
 
     @ColorInt
     private fun getCaptionBackgroundColor(taskInfo: RunningTaskInfo): Int {
+        if (isTransparentBackgroundRequested(taskInfo)) {
+            return Color.TRANSPARENT
+        }
         val materialColorAttr: Int =
             if (isDarkMode()) {
                 if (!taskInfo.isFocused) {
@@ -102,6 +107,10 @@ internal class DesktopModeAppControlsWindowDecorationViewHolder(
     @ColorInt
     private fun getAppNameAndButtonColor(taskInfo: RunningTaskInfo): Int {
         val materialColorAttr = when {
+            isTransparentBackgroundRequested(taskInfo) &&
+                    isLightCaptionBar(taskInfo) -> materialColorOnSecondaryContainer
+            isTransparentBackgroundRequested(taskInfo) &&
+                    !isLightCaptionBar(taskInfo) -> materialColorOnSurface
             isDarkMode() -> materialColorOnSurface
             else -> materialColorOnSecondaryContainer
         }
@@ -132,6 +141,16 @@ internal class DesktopModeAppControlsWindowDecorationViewHolder(
                 Configuration.UI_MODE_NIGHT_YES
     }
 
+    private fun isTransparentBackgroundRequested(taskInfo: RunningTaskInfo): Boolean {
+        val appearance = taskInfo.taskDescription?.statusBarAppearance ?: 0
+        return (appearance and APPEARANCE_TRANSPARENT_CAPTION_BAR_BACKGROUND) != 0
+    }
+
+    private fun isLightCaptionBar(taskInfo: RunningTaskInfo): Boolean {
+        val appearance = taskInfo.taskDescription?.statusBarAppearance ?: 0
+        return (appearance and APPEARANCE_LIGHT_CAPTION_BARS) != 0
+    }
+
     companion object {
         private const val TAG = "DesktopModeAppControlsWindowDecorationViewHolder"
         private const val DARK_THEME_UNFOCUSED_OPACITY = 140 // 55%