Merge "Implement a minimize button on a caption bar" into main

13 files changed, 244 insertions, 17 deletions

diff --git a/libs/WindowManager/Shell/res/drawable/desktop_mode_header_ic_minimize.xml b/libs/WindowManager/Shell/res/drawable/desktop_mode_header_ic_minimize.xml
new file mode 100644
index 000000000000..b35dc022e210
--- /dev/null
+++ b/libs/WindowManager/Shell/res/drawable/desktop_mode_header_ic_minimize.xml
@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ 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.
+  -->
+<vector
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportHeight="24"
+    android:viewportWidth="24">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M6,21V19H18V21Z"/>
+</vector>
diff --git a/libs/WindowManager/Shell/res/layout/desktop_mode_app_header.xml b/libs/WindowManager/Shell/res/layout/desktop_mode_app_header.xml
index 7b31c1420a7c..7dcb3c237c51 100644
--- a/libs/WindowManager/Shell/res/layout/desktop_mode_app_header.xml
+++ b/libs/WindowManager/Shell/res/layout/desktop_mode_app_header.xml
@@ -76,6 +76,18 @@
         android:layout_height="40dp"
         android:layout_weight="1"/>
 
+    <ImageButton
+        android:id="@+id/minimize_window"
+        android:layout_width="44dp"
+        android:layout_height="40dp"
+        android:paddingHorizontal="10dp"
+        android:paddingVertical="8dp"
+        android:layout_marginEnd="8dp"
+        android:contentDescription="@string/minimize_button_text"
+        android:src="@drawable/desktop_mode_header_ic_minimize"
+        android:scaleType="centerCrop"
+        android:gravity="end"/>
+
     <com.android.wm.shell.windowdecor.MaximizeButtonView
         android:id="@+id/maximize_button_view"
         android:layout_width="44dp"
diff --git a/libs/WindowManager/Shell/res/values/dimen.xml b/libs/WindowManager/Shell/res/values/dimen.xml
index 08a746fdf867..2d98a2b675a3 100644
--- a/libs/WindowManager/Shell/res/values/dimen.xml
+++ b/libs/WindowManager/Shell/res/values/dimen.xml
@@ -460,6 +460,11 @@
          start of this area. -->
     <dimen name="desktop_mode_customizable_caption_margin_end">152dp</dimen>
 
+    <!-- The width of the right-aligned region that is taken up by caption elements and extra
+         margins when the caption has the minimize button. This will be merged with the above value
+         once the minimize button becomes default. -->
+    <dimen name="desktop_mode_customizable_caption_with_minimize_button_margin_end">204dp</dimen>
+
     <!-- The default minimum allowed window width when resizing a window in desktop mode. -->
     <dimen name="desktop_mode_minimum_window_width">386dp</dimen>
 
@@ -579,6 +584,13 @@
     <!-- The vertical inset to apply to the app chip's ripple drawable -->
     <dimen name="desktop_mode_header_app_chip_ripple_inset_vertical">4dp</dimen>
 
+    <!-- The corner radius of the minimize button's ripple drawable -->
+    <dimen name="desktop_mode_header_minimize_ripple_radius">18dp</dimen>
+    <!-- The vertical inset to apply to the minimize button's ripple drawable -->
+    <dimen name="desktop_mode_header_minimize_ripple_inset_vertical">4dp</dimen>
+    <!-- The horizontal inset to apply to the minimize button's ripple drawable -->
+    <dimen name="desktop_mode_header_minimize_ripple_inset_horizontal">6dp</dimen>
+
     <!-- The corner radius of the maximize button's ripple drawable -->
     <dimen name="desktop_mode_header_maximize_ripple_radius">18dp</dimen>
     <!-- The vertical inset to apply to the maximize button's ripple drawable -->
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
index d94732681f72..4db8a82eb5af 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
@@ -236,7 +236,8 @@ public abstract class WMShellModule {
             RootTaskDisplayAreaOrganizer rootTaskDisplayAreaOrganizer,
             InteractionJankMonitor interactionJankMonitor,
             AppToWebGenericLinksParser genericLinksParser,
-            MultiInstanceHelper multiInstanceHelper) {
+            MultiInstanceHelper multiInstanceHelper,
+            Optional<DesktopTasksLimiter> desktopTasksLimiter) {
         if (DesktopModeStatus.canEnterDesktopMode(context)) {
             return new DesktopModeWindowDecorViewModel(
                     context,
@@ -257,7 +258,8 @@ public abstract class WMShellModule {
                     rootTaskDisplayAreaOrganizer,
                     interactionJankMonitor,
                     genericLinksParser,
-                    multiInstanceHelper);
+                    multiInstanceHelper,
+                    desktopTasksLimiter);
         }
         return new CaptionWindowDecorViewModel(
                 context,
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
index 33794d242c03..c97066a6e892 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/desktopmode/DesktopTasksController.kt
@@ -431,6 +431,20 @@ class DesktopTasksController(
         taskRepository.addClosingTask(displayId, taskId)
     }
 
+    /**
+     * Perform clean up of the desktop wallpaper activity if the minimized window task is the last
+     * active task.
+     *
+     * @param wct transaction to modify if the last active task is minimized
+     * @param taskId task id of the window that's being minimized
+     */
+    fun onDesktopWindowMinimize(wct: WindowContainerTransaction, taskId: Int) {
+        if (taskRepository.isOnlyVisibleNonClosingTask(taskId)) {
+            removeWallpaperActivity(wct)
+        }
+        // Do not call taskRepository.minimizeTask because it will be called by DekstopTasksLimiter.
+    }
+
     /** Move a task with given `taskId` to fullscreen */
     fun moveToFullscreen(taskId: Int, transitionSource: DesktopModeTransitionSource) {
         shellTaskOrganizer.getRunningTaskInfo(taskId)?.let { task ->
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionHandler.java b/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionHandler.java
index 4284d06a293f..1ffa54103d62 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionHandler.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionHandler.java
@@ -18,6 +18,7 @@ package com.android.wm.shell.freeform;
 
 import static android.app.WindowConfiguration.WINDOWING_MODE_FREEFORM;
 import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
+
 import static com.android.internal.jank.Cuj.CUJ_DESKTOP_MODE_EXIT_MODE_ON_LAST_WINDOW_CLOSE;
 
 import android.animation.Animator;
@@ -116,9 +117,11 @@ public class FreeformTaskTransitionHandler
     }
 
     @Override
-    public void startMinimizedModeTransition(WindowContainerTransaction wct) {
+    public IBinder startMinimizedModeTransition(WindowContainerTransaction wct) {
         final int type = WindowManager.TRANSIT_TO_BACK;
-        mPendingTransitionTokens.add(mTransitions.startTransition(type, wct, this));
+        final IBinder token = mTransitions.startTransition(type, wct, this);
+        mPendingTransitionTokens.add(token);
+        return token;
     }
 
 
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionStarter.java b/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionStarter.java
index 8da4c6ab4b36..ea68a694c3b9 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionStarter.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/freeform/FreeformTaskTransitionStarter.java
@@ -16,6 +16,7 @@
 
 package com.android.wm.shell.freeform;
 
+import android.os.IBinder;
 import android.window.WindowContainerTransaction;
 
 /**
@@ -38,8 +39,9 @@ public interface FreeformTaskTransitionStarter {
      *
      * @param wct the {@link WindowContainerTransaction} that changes the windowing mode
      *
+     * @return the started transition
      */
-    void startMinimizedModeTransition(WindowContainerTransaction wct);
+    IBinder startMinimizedModeTransition(WindowContainerTransaction wct);
 
     /**
      * Starts close window transition
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
index 457b5112076e..b1cb834db9bf 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
@@ -56,6 +56,7 @@ import android.graphics.Region;
 import android.hardware.input.InputManager;
 import android.net.Uri;
 import android.os.Handler;
+import android.os.IBinder;
 import android.os.Looper;
 import android.os.RemoteException;
 import android.os.UserHandle;
@@ -100,6 +101,7 @@ import com.android.wm.shell.common.desktopmode.DesktopModeTransitionSource;
 import com.android.wm.shell.desktopmode.DesktopModeVisualIndicator;
 import com.android.wm.shell.desktopmode.DesktopTasksController;
 import com.android.wm.shell.desktopmode.DesktopTasksController.SnapPosition;
+import com.android.wm.shell.desktopmode.DesktopTasksLimiter;
 import com.android.wm.shell.desktopmode.DesktopWallpaperActivity;
 import com.android.wm.shell.freeform.FreeformTaskTransitionStarter;
 import com.android.wm.shell.shared.annotations.ShellBackgroundThread;
@@ -150,6 +152,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
     private final InputManager mInputManager;
     private final InteractionJankMonitor mInteractionJankMonitor;
     private final MultiInstanceHelper mMultiInstanceHelper;
+    private final Optional<DesktopTasksLimiter> mDesktopTasksLimiter;
     private boolean mTransitionDragActive;
 
     private SparseArray<EventReceiver> mEventReceiversByDisplay = new SparseArray<>();
@@ -211,7 +214,8 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
             RootTaskDisplayAreaOrganizer rootTaskDisplayAreaOrganizer,
             InteractionJankMonitor interactionJankMonitor,
             AppToWebGenericLinksParser genericLinksParser,
-            MultiInstanceHelper multiInstanceHelper
+            MultiInstanceHelper multiInstanceHelper,
+            Optional<DesktopTasksLimiter> desktopTasksLimiter
     ) {
         this(
                 context,
@@ -236,7 +240,8 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 SurfaceControl.Transaction::new,
                 rootTaskDisplayAreaOrganizer,
                 new SparseArray<>(),
-                interactionJankMonitor);
+                interactionJankMonitor,
+                desktopTasksLimiter);
     }
 
     @VisibleForTesting
@@ -263,7 +268,8 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
             Supplier<SurfaceControl.Transaction> transactionFactory,
             RootTaskDisplayAreaOrganizer rootTaskDisplayAreaOrganizer,
             SparseArray<DesktopModeWindowDecoration> windowDecorByTaskId,
-            InteractionJankMonitor interactionJankMonitor) {
+            InteractionJankMonitor interactionJankMonitor,
+            Optional<DesktopTasksLimiter> desktopTasksLimiter) {
         mContext = context;
         mMainExecutor = shellExecutor;
         mMainHandler = mainHandler;
@@ -290,6 +296,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
         mSysUIPackageName = mContext.getResources().getString(
                 com.android.internal.R.string.config_systemUi);
         mInteractionJankMonitor = interactionJankMonitor;
+        mDesktopTasksLimiter = desktopTasksLimiter;
         mOnDisplayChangingListener = (displayId, fromRotation, toRotation, displayAreaInfo, t) -> {
             DesktopModeWindowDecoration decoration;
             RunningTaskInfo taskInfo;
@@ -615,6 +622,12 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 //  {@link DesktopModeWindowDecoration#setOnMaximizeOrRestoreClickListener}, which
                 //  should shared with the maximize menu's maximize/restore actions.
                 onMaximizeOrRestore(decoration.mTaskInfo.taskId, "caption_bar_button");
+            } else if (id == R.id.minimize_window) {
+                final WindowContainerTransaction wct = new WindowContainerTransaction();
+                mDesktopTasksController.onDesktopWindowMinimize(wct, mTaskId);
+                final IBinder transition = mTaskOperations.minimizeTask(mTaskToken, wct);
+                mDesktopTasksLimiter.ifPresent(limiter ->
+                        limiter.addPendingMinimizeChange(transition, mDisplayId, mTaskId));
             }
         }
 
@@ -628,7 +641,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
             }
             if (id != R.id.caption_handle && id != R.id.desktop_mode_caption
                     && id != R.id.open_menu_button && id != R.id.close_window
-                    && id != R.id.maximize_window) {
+                    && id != R.id.maximize_window && id != R.id.minimize_window) {
                 return false;
             }
 
@@ -768,7 +781,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 return true;
             }
             final boolean touchingButton = (id == R.id.close_window || id == R.id.maximize_window
-                    || id == R.id.open_menu_button);
+                    || id == R.id.open_menu_button || id == R.id.minimize_window);
             switch (e.getActionMasked()) {
                 case MotionEvent.ACTION_DOWN: {
                     mDragPointerId = e.getPointerId(0);
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
index 75a6cd7b720e..8e87d0ff33c6 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
@@ -643,6 +643,10 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
             final RelayoutParams.OccludingCaptionElement controlsElement =
                     new RelayoutParams.OccludingCaptionElement();
             controlsElement.mWidthResId = R.dimen.desktop_mode_customizable_caption_margin_end;
+            if (Flags.enableMinimizeButton()) {
+                controlsElement.mWidthResId =
+                      R.dimen.desktop_mode_customizable_caption_with_minimize_button_margin_end;
+            }
             controlsElement.mAlignment = RelayoutParams.OccludingCaptionElement.Alignment.END;
             relayoutParams.mOccludingCaptionElements.add(controlsElement);
         } else if (isAppHandle && !Flags.enableAdditionalWindowsAboveStatusBar()) {
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/TaskOperations.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/TaskOperations.java
index ad238c35dd83..61b93932013c 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/TaskOperations.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/TaskOperations.java
@@ -23,6 +23,7 @@ import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
 import android.app.ActivityManager.RunningTaskInfo;
 import android.content.Context;
 import android.hardware.input.InputManager;
+import android.os.IBinder;
 import android.os.SystemClock;
 import android.util.Log;
 import android.view.InputDevice;
@@ -84,13 +85,17 @@ class TaskOperations {
         }
     }
 
-    void minimizeTask(WindowContainerToken taskToken) {
-        WindowContainerTransaction wct = new WindowContainerTransaction();
+    IBinder minimizeTask(WindowContainerToken taskToken) {
+        return minimizeTask(taskToken, new WindowContainerTransaction());
+    }
+
+    IBinder minimizeTask(WindowContainerToken taskToken, WindowContainerTransaction wct) {
         wct.reorder(taskToken, false);
         if (Transitions.ENABLE_SHELL_TRANSITIONS) {
-            mTransitionStarter.startMinimizedModeTransition(wct);
+            return mTransitionStarter.startMinimizedModeTransition(wct);
         } else {
             mSyncQueue.queue(wct);
+            return null;
         }
     }
 
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHeaderViewHolder.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHeaderViewHolder.kt
index d0eb6da36702..033d69583725 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHeaderViewHolder.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHeaderViewHolder.kt
@@ -35,6 +35,7 @@ import androidx.compose.material3.dynamicDarkColorScheme
 import androidx.compose.material3.dynamicLightColorScheme
 import androidx.compose.ui.graphics.toArgb
 import androidx.core.content.withStyledAttributes
+import androidx.core.view.isGone
 import androidx.core.view.isVisible
 import com.android.internal.R.attr.materialColorOnSecondaryContainer
 import com.android.internal.R.attr.materialColorOnSurface
@@ -42,6 +43,7 @@ import com.android.internal.R.attr.materialColorSecondaryContainer
 import com.android.internal.R.attr.materialColorSurfaceContainerHigh
 import com.android.internal.R.attr.materialColorSurfaceContainerLow
 import com.android.internal.R.attr.materialColorSurfaceDim
+import com.android.window.flags.Flags.enableMinimizeButton
 import com.android.wm.shell.R
 import com.android.wm.shell.shared.desktopmode.DesktopModeFlags
 import com.android.wm.shell.windowdecor.MaximizeButtonView
@@ -82,9 +84,9 @@ internal class AppHeaderViewHolder(
         .getDimensionPixelSize(R.dimen.desktop_mode_header_buttons_ripple_radius)
 
     /**
-     * The app chip, maximize and close button's height extends to the top & bottom edges of the
-     * header, and their width may be larger than their height. This is by design to increase the
-     * clickable and hover-able bounds of the view as much as possible. However, to prevent the
+     * The app chip, minimize, maximize and close button's height extends to the top & bottom edges
+     * of the header, and their width may be larger than their height. This is by design to increase
+     * the clickable and hover-able bounds of the view as much as possible. However, to prevent the
      * ripple drawable from being as large as the views (and asymmetrical), insets are applied to
      * the background ripple drawable itself to give the appearance of a smaller button
      * (with padding between itself and the header edges / sibling buttons) but without affecting
@@ -94,6 +96,12 @@ internal class AppHeaderViewHolder(
         vertical = context.resources
             .getDimensionPixelSize(R.dimen.desktop_mode_header_app_chip_ripple_inset_vertical)
     )
+    private val minimizeDrawableInsets = DrawableInsets(
+        vertical = context.resources
+            .getDimensionPixelSize(R.dimen.desktop_mode_header_minimize_ripple_inset_vertical),
+        horizontal = context.resources
+            .getDimensionPixelSize(R.dimen.desktop_mode_header_minimize_ripple_inset_horizontal)
+    )
     private val maximizeDrawableInsets = DrawableInsets(
         vertical = context.resources
             .getDimensionPixelSize(R.dimen.desktop_mode_header_maximize_ripple_inset_vertical),
@@ -115,6 +123,7 @@ internal class AppHeaderViewHolder(
     private val maximizeButtonView: MaximizeButtonView =
             rootView.requireViewById(R.id.maximize_button_view)
     private val maximizeWindowButton: ImageButton = rootView.requireViewById(R.id.maximize_window)
+    private val minimizeWindowButton: ImageButton = rootView.requireViewById(R.id.minimize_window)
     private val appNameTextView: TextView = rootView.requireViewById(R.id.application_name)
     private val appIconImageView: ImageView = rootView.requireViewById(R.id.application_icon)
     val appNameTextWidth: Int
@@ -131,6 +140,8 @@ internal class AppHeaderViewHolder(
         maximizeWindowButton.setOnGenericMotionListener(onCaptionGenericMotionListener)
         maximizeWindowButton.onLongClickListener = onLongClickListener
         closeWindowButton.setOnTouchListener(onCaptionTouchListener)
+        minimizeWindowButton.setOnClickListener(onCaptionButtonClickListener)
+        minimizeWindowButton.setOnTouchListener(onCaptionTouchListener)
         appNameTextView.text = appName
         appIconImageView.setImageBitmap(appIconBitmap)
         maximizeButtonView.onHoverAnimationFinishedListener =
@@ -157,11 +168,13 @@ internal class AppHeaderViewHolder(
         val alpha = Color.alpha(color)
         closeWindowButton.imageTintList = ColorStateList.valueOf(color)
         maximizeWindowButton.imageTintList = ColorStateList.valueOf(color)
+        minimizeWindowButton.imageTintList = ColorStateList.valueOf(color)
         expandMenuButton.imageTintList = ColorStateList.valueOf(color)
         appNameTextView.isVisible = !taskInfo.isTransparentCaptionBarAppearance
         appNameTextView.setTextColor(color)
         appIconImageView.imageAlpha = alpha
         maximizeWindowButton.imageAlpha = alpha
+        minimizeWindowButton.imageAlpha = alpha
         closeWindowButton.imageAlpha = alpha
         expandMenuButton.imageAlpha = alpha
         context.withStyledAttributes(
@@ -176,8 +189,10 @@ internal class AppHeaderViewHolder(
             openMenuButton.background = getDrawable(0)
             maximizeWindowButton.background = getDrawable(1)
             closeWindowButton.background = getDrawable(1)
+            minimizeWindowButton.background = getDrawable(1)
         }
         maximizeButtonView.setAnimationTints(isDarkMode())
+        minimizeWindowButton.isGone = !enableMinimizeButton()
     }
 
     private fun bindDataWithThemedHeaders(taskInfo: RunningTaskInfo) {
@@ -212,6 +227,16 @@ internal class AppHeaderViewHolder(
             }
             appIconImageView.imageAlpha = foregroundAlpha
         }
+        // Minimize button.
+        minimizeWindowButton.apply {
+            imageTintList = colorStateList
+            background = createRippleDrawable(
+                color = foregroundColor,
+                cornerRadius = headerButtonsRippleRadius,
+                drawableInsets = minimizeDrawableInsets
+            )
+        }
+        minimizeWindowButton.isGone = !enableMinimizeButton()
         // Maximize button.
         maximizeButtonView.setAnimationTints(
             darkMode = header.appTheme == Theme.DARK,
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
index a841e168af18..2e0af273f2b6 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/desktopmode/DesktopTasksControllerTest.kt
@@ -1429,6 +1429,78 @@ class DesktopTasksControllerTest : ShellTestCase() {
   }
 
   @Test
+  fun onDesktopWindowMinimize_noActiveTask_doesntUpdateTransaction() {
+    val wct = WindowContainerTransaction()
+    controller.onDesktopWindowMinimize(wct, taskId = 1)
+    // Nothing happens.
+    assertThat(wct.hierarchyOps).isEmpty()
+  }
+
+  @Test
+  fun onDesktopWindowMinimize_singleActiveTask_noWallpaperActivityToken_doesntUpdateTransaction() {
+    val task = setUpFreeformTask()
+    val wct = WindowContainerTransaction()
+    controller.onDesktopWindowMinimize(wct, taskId = task.taskId)
+    // Nothing happens.
+    assertThat(wct.hierarchyOps).isEmpty()
+  }
+
+  @Test
+  fun onDesktopWindowMinimize_singleActiveTask_hasWallpaperActivityToken_removesWallpaper() {
+    val task = setUpFreeformTask()
+    val wallpaperToken = MockToken().token()
+    taskRepository.wallpaperActivityToken = wallpaperToken
+
+    val wct = WindowContainerTransaction()
+    // The only active task is being minimized.
+    controller.onDesktopWindowMinimize(wct, taskId = task.taskId)
+    // Adds remove wallpaper operation
+    wct.assertRemoveAt(index = 0, wallpaperToken)
+  }
+
+  @Test
+  fun onDesktopWindowMinimize_singleActiveTask_alreadyMinimized_doesntUpdateTransaction() {
+    val task = setUpFreeformTask()
+    val wallpaperToken = MockToken().token()
+    taskRepository.wallpaperActivityToken = wallpaperToken
+    taskRepository.minimizeTask(DEFAULT_DISPLAY, task.taskId)
+
+    val wct = WindowContainerTransaction()
+    // The only active task is already minimized.
+    controller.onDesktopWindowMinimize(wct, taskId = task.taskId)
+    // Doesn't modify transaction
+    assertThat(wct.hierarchyOps).isEmpty()
+  }
+
+  @Test
+  fun onDesktopWindowMinimize_multipleActiveTasks_doesntUpdateTransaction() {
+    val task1 = setUpFreeformTask()
+    setUpFreeformTask()
+    val wallpaperToken = MockToken().token()
+    taskRepository.wallpaperActivityToken = wallpaperToken
+
+    val wct = WindowContainerTransaction()
+    controller.onDesktopWindowMinimize(wct, taskId = task1.taskId)
+    // Doesn't modify transaction
+    assertThat(wct.hierarchyOps).isEmpty()
+  }
+
+  @Test
+  fun onDesktopWindowMinimize_multipleActiveTasks_minimizesTheOnlyVisibleTask_removesWallpaper() {
+    val task1 = setUpFreeformTask()
+    val task2 = setUpFreeformTask()
+    val wallpaperToken = MockToken().token()
+    taskRepository.wallpaperActivityToken = wallpaperToken
+    taskRepository.minimizeTask(DEFAULT_DISPLAY, task2.taskId)
+
+    val wct = WindowContainerTransaction()
+    // task1 is the only visible task as task2 is minimized.
+    controller.onDesktopWindowMinimize(wct, taskId = task1.taskId)
+    // Adds remove wallpaper operation
+    wct.assertRemoveAt(index = 0, wallpaperToken)
+  }
+
+  @Test
   fun handleRequest_fullscreenTask_freeformVisible_returnSwitchToFreeformWCT() {
     assumeTrue(ENABLE_SHELL_TRANSITIONS)
 
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt
index 4d6b3b907a65..543ec84e79f6 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt
@@ -82,6 +82,7 @@ import com.android.wm.shell.common.SyncTransactionQueue
 import com.android.wm.shell.common.desktopmode.DesktopModeTransitionSource
 import com.android.wm.shell.desktopmode.DesktopTasksController
 import com.android.wm.shell.desktopmode.DesktopTasksController.SnapPosition
+import com.android.wm.shell.desktopmode.DesktopTasksLimiter
 import com.android.wm.shell.freeform.FreeformTaskTransitionStarter
 import com.android.wm.shell.shared.desktopmode.DesktopModeStatus
 import com.android.wm.shell.splitscreen.SplitScreenController
@@ -112,6 +113,7 @@ import org.mockito.Mockito.never
 import org.mockito.Mockito.times
 import org.mockito.Mockito.verify
 import org.mockito.kotlin.any
+import org.mockito.kotlin.anyOrNull
 import org.mockito.kotlin.argThat
 import org.mockito.kotlin.argumentCaptor
 import org.mockito.kotlin.doNothing
@@ -163,6 +165,7 @@ class DesktopModeWindowDecorViewModelTests : ShellTestCase() {
     @Mock private lateinit var mockToast: Toast
     private val bgExecutor = TestShellExecutor()
     @Mock private lateinit var mockMultiInstanceHelper: MultiInstanceHelper
+    @Mock private lateinit var mockTasksLimiter: DesktopTasksLimiter
     private lateinit var spyContext: TestableContext
 
     private val transactionFactory = Supplier<SurfaceControl.Transaction> {
@@ -215,7 +218,8 @@ class DesktopModeWindowDecorViewModelTests : ShellTestCase() {
                 transactionFactory,
                 mockRootTaskDisplayAreaOrganizer,
                 windowDecorByTaskIdSpy,
-                mockInteractionJankMonitor
+                mockInteractionJankMonitor,
+                Optional.of(mockTasksLimiter)
         )
         desktopModeWindowDecorViewModel.setSplitScreenController(mockSplitScreenController)
         whenever(mockDisplayController.getDisplayLayout(any())).thenReturn(mockDisplayLayout)
@@ -388,6 +392,39 @@ class DesktopModeWindowDecorViewModelTests : ShellTestCase() {
     }
 
     @Test
+    @EnableFlags(Flags.FLAG_ENABLE_MINIMIZE_BUTTON)
+    fun testMinimizeButtonInFreefrom_minimizeWindow() {
+        val onClickListenerCaptor = forClass(View.OnClickListener::class.java)
+                as ArgumentCaptor<View.OnClickListener>
+        val decor = createOpenTaskDecoration(
+            windowingMode = WINDOWING_MODE_FREEFORM,
+            onCaptionButtonClickListener = onClickListenerCaptor
+        )
+
+        val view = mock(View::class.java)
+        whenever(view.id).thenReturn(R.id.minimize_window)
+
+        val freeformTaskTransitionStarter = mock(FreeformTaskTransitionStarter::class.java)
+        desktopModeWindowDecorViewModel
+            .setFreeformTaskTransitionStarter(freeformTaskTransitionStarter)
+
+        onClickListenerCaptor.value.onClick(view)
+
+        val transactionCaptor = argumentCaptor<WindowContainerTransaction>()
+        verify(freeformTaskTransitionStarter)
+            .startMinimizedModeTransition(transactionCaptor.capture())
+        val wct = transactionCaptor.firstValue
+
+        verify(mockTasksLimiter).addPendingMinimizeChange(
+                anyOrNull(), eq(DEFAULT_DISPLAY), eq(decor.mTaskInfo.taskId))
+
+        assertEquals(1, wct.getHierarchyOps().size)
+        assertEquals(HierarchyOp.HIERARCHY_OP_TYPE_REORDER, wct.getHierarchyOps().get(0).getType())
+        assertFalse(wct.getHierarchyOps().get(0).getToTop())
+        assertEquals(decor.mTaskInfo.token.asBinder(), wct.getHierarchyOps().get(0).getContainer())
+    }
+
+    @Test
     @EnableFlags(Flags.FLAG_ENABLE_DESKTOP_WINDOWING_MODALS_POLICY)
     fun testDecorationIsCreatedForTopTranslucentActivitiesWithStyleFloating() {
         val task = createTask(windowingMode = WINDOWING_MODE_FULLSCREEN, focused = true).apply {