Fix 3253629: Tweaks to recent apps

This change reduces the overall timing of showing recents to make it
feel more snappy.

It also removes the first item from the list, which is assumed to be
the current app or the home screen, depending on which is currently
showing. This allows the use of muscle memory for switching between
two tasks quickly.

Change-Id: I04713c41ea235483ea4d3f712a84c56b0174394f

2 files changed, 12 insertions, 17 deletions

diff --git a/packages/SystemUI/res/layout-xlarge/status_bar_recent_panel.xml b/packages/SystemUI/res/layout-xlarge/status_bar_recent_panel.xml
index 97cbfca..cc044a1 100644
--- a/packages/SystemUI/res/layout-xlarge/status_bar_recent_panel.xml
+++ b/packages/SystemUI/res/layout-xlarge/status_bar_recent_panel.xml
@@ -27,15 +27,6 @@
     android:id="@+id/recents_bg_protect"
     android:orientation="vertical">
 
-    <TextView android:id="@+id/recents_no_recents"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content"
-        android:text="@string/recent_tasks_empty"
-        android:textSize="22dip"
-        android:gravity="center_horizontal|center_vertical"
-        android:visibility="gone">
-    </TextView>
-
     <View
         android:layout_width="match_parent"
         android:layout_height="0dip"
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java b/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java
index 1301329..e0f37ca 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/tablet/RecentAppsPanel.java
@@ -46,6 +46,7 @@ import android.util.DisplayMetrics;
 import android.util.Log;
 import android.view.View;
 import android.view.View.OnClickListener;
+import android.view.animation.AccelerateInterpolator;
 import android.view.animation.DecelerateInterpolator;
 import android.widget.ImageView;
 import android.widget.LinearLayout;
@@ -54,13 +55,15 @@ import android.widget.TextView;
 import com.android.systemui.R;
 
 public class RecentAppsPanel extends LinearLayout implements StatusBarPanel, OnClickListener {
+    private static final int COLLAPSE_DURATION = 360;
     private static final String TAG = "RecentAppsPanel";
     private static final boolean DEBUG = TabletStatusBar.DEBUG;
     private static final int DISPLAY_TASKS_PORTRAIT = 8;
     private static final int DISPLAY_TASKS_LANDSCAPE = 5; // number of recent tasks to display
     private static final int MAX_TASKS = DISPLAY_TASKS_PORTRAIT + 2; // allow extra for non-apps
+    private static final int STAGGER_ANIMATION_DELAY = 30;
+    private static final long ALPHA_ANIMATION_DURATION = 120;
     private TabletStatusBar mBar;
-    private TextView mNoRecents;
     private LinearLayout mRecentsContainer;
     private View mRecentsGlowView;
     private ArrayList<ActivityDescription> mActivityDescriptions;
@@ -123,7 +126,6 @@ public class RecentAppsPanel extends LinearLayout implements StatusBarPanel, OnC
     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();
-        mNoRecents = (TextView) findViewById(R.id.recents_no_recents);
         mRecentsContainer = (LinearLayout) findViewById(R.id.recents_container);
         mRecentsGlowView = findViewById(R.id.recents_glow);
         mBackgroundProtector = (View) findViewById(R.id.recents_bg_protect);
@@ -193,7 +195,10 @@ public class RecentAppsPanel extends LinearLayout implements StatusBarPanel, OnC
                     .resolveActivityInfo(pm, 0);
 
         int numTasks = recentTasks.size();
-        for (int i = 0, index = 0; i < numTasks && (index < MAX_TASKS); ++i) {
+
+        // skip the first activity - assume it's either the home screen or the current app.
+        final int first = 1;
+        for (int i = first, index = 0; i < numTasks && (index < MAX_TASKS); ++i) {
             final ActivityManager.RecentTaskInfo recentInfo = recentTasks.get(i);
 
             Intent intent = new Intent(recentInfo.baseIntent);
@@ -297,22 +302,21 @@ public class RecentAppsPanel extends LinearLayout implements StatusBarPanel, OnC
             if (animate) {
                 view.setAlpha(initialAlpha);
                 ObjectAnimator anim = ObjectAnimator.ofFloat(view, "alpha", initialAlpha, 1.0f);
-                anim.setDuration(200);
-                anim.setStartDelay((last-i)*80);
+                anim.setDuration(ALPHA_ANIMATION_DURATION);
+                anim.setStartDelay((last-i) * STAGGER_ANIMATION_DELAY);
                 anim.setInterpolator(interp);
                 anims.add(anim);
             }
         }
 
         int views = mRecentsContainer.getChildCount();
-        mNoRecents.setVisibility(View.GONE); // views == 0 ? View.VISIBLE : View.GONE);
         mRecentsContainer.setVisibility(views > 0 ? View.VISIBLE : View.GONE);
         mRecentsGlowView.setVisibility(views > 0 ? View.VISIBLE : View.GONE);
 
         if (animate && views > 0) {
             ObjectAnimator anim = ObjectAnimator.ofFloat(mRecentsGlowView, "alpha",
                     initialAlpha, 1.0f);
-            anim.setDuration((last-first)*80);
+            anim.setDuration((last-first) * STAGGER_ANIMATION_DELAY);
             anim.setInterpolator(interp);
             anims.add(anim);
         }
@@ -320,7 +324,7 @@ public class RecentAppsPanel extends LinearLayout implements StatusBarPanel, OnC
         if (animate) {
             ObjectAnimator anim = ObjectAnimator.ofFloat(mBackgroundProtector, "alpha",
                     initialAlpha, 1.0f);
-            anim.setDuration(last*80);
+            anim.setDuration(last * STAGGER_ANIMATION_DELAY);
             anim.setInterpolator(interp);
             anims.add(anim);
         }