Add task content animation property

Add API to animate task item content transition from one set of task
content (icon, thumbnail) to another. To do this, we provide two things
to the caller: startContentAnimation which allows the caller to set the
icon, thumbnail, and label to animate to and the
CONTENT_TRANSITION_PROGRESS property which the caller can use to control
the transition progress.

We will eventually hook this up to onBindViewHolder for the task adapter
when there is a data change event to prepare to animate content in.
Currently it still changes immediately.

Bug: 114136250
Test: Builds
Change-Id: I16e9b757ee91be54fe8cba6780b399e3cc313e3e
(cherry picked from commit a3d80d102e108b17adce49c440c0f4b84d3867e5)

3 files changed, 86 insertions, 6 deletions

diff --git a/go/quickstep/src/com/android/quickstep/TaskAdapter.java b/go/quickstep/src/com/android/quickstep/TaskAdapter.java
index 674fcae91..66c074bdd 100644
--- a/go/quickstep/src/com/android/quickstep/TaskAdapter.java
+++ b/go/quickstep/src/com/android/quickstep/TaskAdapter.java
@@ -94,7 +94,7 @@ public final class TaskAdapter extends Adapter<TaskHolder> {
             return;
         }
         Task task = tasks.get(position);
-        holder.bindTask(task);
+        holder.bindTask(task, false /* willAnimate */);
         mLoader.loadTaskIconAndLabel(task, () -> {
             // Ensure holder still has the same task.
             if (Objects.equals(task, holder.getTask())) {
@@ -110,6 +110,13 @@ public final class TaskAdapter extends Adapter<TaskHolder> {
     }
 
     @Override
+    public void onBindViewHolder(@NonNull TaskHolder holder, int position,
+            @NonNull List<Object> payloads) {
+        // TODO: Bind task in preparation for animation. For now, we apply UI changes immediately.
+        super.onBindViewHolder(holder, position, payloads);
+    }
+
+    @Override
     public void onViewAttachedToWindow(@NonNull TaskHolder holder) {
         if (holder.getTask() == null) {
             return;
diff --git a/go/quickstep/src/com/android/quickstep/TaskHolder.java b/go/quickstep/src/com/android/quickstep/TaskHolder.java
index 98dc98931..91a3534c0 100644
--- a/go/quickstep/src/com/android/quickstep/TaskHolder.java
+++ b/go/quickstep/src/com/android/quickstep/TaskHolder.java
@@ -15,6 +15,9 @@
  */
 package com.android.quickstep;
 
+import android.graphics.Bitmap;
+
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.recyclerview.widget.RecyclerView.ViewHolder;
 
@@ -40,13 +43,28 @@ public final class TaskHolder extends ViewHolder {
     }
 
     /**
-     * Bind a task to the holder, resetting the view and preparing it for content to load in.
+     * Bind the task model to the holder. This will take the current task content in the task
+     * object (i.e. icon, thumbnail, label) and either apply the content immediately or simply bind
+     * the content to animate to at a later time. If the task does not have all its content loaded,
+     * the view will prepare appropriate default placeholders and it is the callers responsibility
+     * to change them at a later time.
+     *
+     * Regardless of whether it is animating, input handlers will be bound immediately (see
+     * {@link TaskActionController}).
      *
      * @param task the task to bind to the view
+     * @param willAnimate true if UI should animate in later, false if it should apply immediately
      */
-    public void bindTask(Task task) {
+    public void bindTask(@NonNull Task task, boolean willAnimate) {
         mTask = task;
-        mTaskItemView.resetTaskItemView();
+        Bitmap thumbnail = (task.thumbnail != null) ? task.thumbnail.thumbnail : null;
+        if (willAnimate) {
+            mTaskItemView.startContentAnimation(task.icon, thumbnail, task.titleDescription);
+        } else {
+            mTaskItemView.setIcon(task.icon);
+            mTaskItemView.setThumbnail(thumbnail);
+            mTaskItemView.setLabel(task.titleDescription);
+        }
     }
 
     /**
diff --git a/go/quickstep/src/com/android/quickstep/views/TaskItemView.java b/go/quickstep/src/com/android/quickstep/views/TaskItemView.java
index 0a3fba840..a8fc78a33 100644
--- a/go/quickstep/src/com/android/quickstep/views/TaskItemView.java
+++ b/go/quickstep/src/com/android/quickstep/views/TaskItemView.java
@@ -21,6 +21,7 @@ import android.graphics.Bitmap;
 import android.graphics.drawable.BitmapDrawable;
 import android.graphics.drawable.Drawable;
 import android.util.AttributeSet;
+import android.util.FloatProperty;
 import android.view.View;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
@@ -39,15 +40,37 @@ public final class TaskItemView extends LinearLayout {
     private static final String DEFAULT_LABEL = "...";
     private final Drawable mDefaultIcon;
     private final Drawable mDefaultThumbnail;
+    private final TaskLayerDrawable mIconDrawable;
+    private final TaskLayerDrawable mThumbnailDrawable;
     private TextView mLabelView;
     private ImageView mIconView;
     private ImageView mThumbnailView;
+    private float mContentTransitionProgress;
+
+    /**
+     * Property representing the content transition progress of the view. 1.0f represents that the
+     * currently bound icon, thumbnail, and label are fully animated in and visible.
+     */
+    public static FloatProperty CONTENT_TRANSITION_PROGRESS =
+            new FloatProperty<TaskItemView>("taskContentTransitionProgress") {
+                @Override
+                public void setValue(TaskItemView view, float progress) {
+                    view.setContentTransitionProgress(progress);
+                }
+
+                @Override
+                public Float get(TaskItemView view) {
+                    return view.mContentTransitionProgress;
+                }
+            };
 
     public TaskItemView(Context context, AttributeSet attrs) {
         super(context, attrs);
         Resources res = context.getResources();
         mDefaultIcon = res.getDrawable(android.R.drawable.sym_def_app_icon, context.getTheme());
         mDefaultThumbnail = res.getDrawable(R.drawable.default_thumbnail, context.getTheme());
+        mIconDrawable = new TaskLayerDrawable(context);
+        mThumbnailDrawable = new TaskLayerDrawable(context);
     }
 
     @Override
@@ -56,6 +79,12 @@ public final class TaskItemView extends LinearLayout {
         mLabelView = findViewById(R.id.task_label);
         mThumbnailView = findViewById(R.id.task_thumbnail);
         mIconView = findViewById(R.id.task_icon);
+
+        mThumbnailView.setImageDrawable(mThumbnailDrawable);
+        mIconView.setImageDrawable(mIconDrawable);
+
+        resetTaskItemView();
+        CONTENT_TRANSITION_PROGRESS.setValue(this, 1.0f);
     }
 
     /**
@@ -74,6 +103,7 @@ public final class TaskItemView extends LinearLayout {
      */
     public void setLabel(@Nullable String label) {
         mLabelView.setText(getSafeLabel(label));
+        // TODO: Animation for label
     }
 
     /**
@@ -86,7 +116,7 @@ public final class TaskItemView extends LinearLayout {
         // The icon proper is actually smaller than the drawable and has "padding" on the side for
         // the purpose of drawing the shadow, allowing the icon to pop up, so we need to scale the
         // view if we want the icon to be flush with the bottom of the thumbnail.
-        mIconView.setImageDrawable(getSafeIcon(icon));
+        mIconDrawable.setCurrentDrawable(getSafeIcon(icon));
     }
 
     /**
@@ -95,13 +125,38 @@ public final class TaskItemView extends LinearLayout {
      * @param thumbnail task thumbnail for the task
      */
     public void setThumbnail(@Nullable Bitmap thumbnail) {
-        mThumbnailView.setImageDrawable(getSafeThumbnail(thumbnail));
+        mThumbnailDrawable.setCurrentDrawable(getSafeThumbnail(thumbnail));
     }
 
     public View getThumbnailView() {
         return mThumbnailView;
     }
 
+    /**
+     * Start a new animation from the current task content to the specified new content. The caller
+     * is responsible for the actual animation control via the property
+     * {@link #CONTENT_TRANSITION_PROGRESS}.
+     *
+     * @param endIcon the icon to animate to
+     * @param endThumbnail the thumbnail to animate to
+     * @param endLabel the label to animate to
+     */
+    public void startContentAnimation(@Nullable Drawable endIcon, @Nullable Bitmap endThumbnail,
+            @Nullable String endLabel) {
+        mIconDrawable.startNewTransition(getSafeIcon(endIcon));
+        mThumbnailDrawable.startNewTransition(getSafeThumbnail(endThumbnail));
+        // TODO: Animation for label
+
+        setContentTransitionProgress(0.0f);
+    }
+
+    private void setContentTransitionProgress(float progress) {
+        mContentTransitionProgress = progress;
+        mIconDrawable.setTransitionProgress(progress);
+        mThumbnailDrawable.setTransitionProgress(progress);
+        // TODO: Animation for label
+    }
+
     private @NonNull Drawable getSafeIcon(@Nullable Drawable icon) {
         return (icon != null) ? icon : mDefaultIcon;
     }