Scale AppPair background on hover.

Fix: 342133586
Test: manual.
Flag: EXEMPT bugfix
Change-Id: I2846b5543076688a90e8b9067f848c59e4081ea2

src/com/android/launcher3/Utilities.java

@@ -380,6 +380,28 @@ public final class Utilities {
         outPivot.y = dst.top + dst.height() * pivotYPct;
     }
 
+    /**
+     * Scales a {@code RectF} in place about a specified pivot point.
+     *
+     * <p>This method modifies the given {@code RectF} directly to scale it proportionally
+     * by the given {@code scale}, while preserving its center at the specified
+     * {@code (pivotX, pivotY)} coordinates.
+     *
+     * @param rectF the {@code RectF} to scale, modified directly.
+     * @param pivotX the x-coordinate of the pivot point about which to scale.
+     * @param pivotY the y-coordinate of the pivot point about which to scale.
+     * @param scale the factor by which to scale the rectangle. Values less than 1 will
+     *                    shrink the rectangle, while values greater than 1 will enlarge it.
+     */
+    public static void scaleRectFAboutPivot(RectF rectF, float pivotX, float pivotY, float scale) {
+        rectF.offset(-pivotX, -pivotY);
+        rectF.left *= scale;
+        rectF.top *= scale;
+        rectF.right *= scale;
+        rectF.bottom *= scale;
+        rectF.offset(pivotX, pivotY);
+    }
+
     /**
      * Maps t from one range to another range.
      * @param t The value to map.

src/com/android/launcher3/apppairs/AppPairIcon.java

@@ -18,10 +18,12 @@ package com.android.launcher3.apppairs;
 
 import static com.android.launcher3.BubbleTextView.DISPLAY_FOLDER;
 
+import android.animation.ObjectAnimator;
 import android.content.Context;
 import android.graphics.Paint;
 import android.graphics.Rect;
 import android.util.AttributeSet;
+import android.util.FloatProperty;
 import android.view.LayoutInflater;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
@@ -54,6 +56,26 @@ import java.util.function.Predicate;
 public class AppPairIcon extends FrameLayout implements DraggableView, Reorderable {
     private static final String TAG = "AppPairIcon";
 
+    // The duration of the scaling animation on hover enter/exit.
+    private static final int HOVER_SCALE_DURATION = 150;
+    // The default scale of the icon when not hovered.
+    private static final Float HOVER_SCALE_DEFAULT = 1f;
+    // The max scale of the icon when hovered.
+    private static final Float HOVER_SCALE_MAX = 1.1f;
+    // Animates the scale of the icon background on hover.
+    private static final FloatProperty<AppPairIcon> HOVER_SCALE_PROPERTY =
+            new FloatProperty<>("hoverScale") {
+                @Override
+                public void setValue(AppPairIcon view, float scale) {
+                    view.mIconGraphic.setHoverScale(scale);
+                }
+
+                @Override
+                public Float get(AppPairIcon view) {
+                    return view.mIconGraphic.getHoverScale();
+                }
+            };
+
     // A view that holds the app pair icon graphic.
     private AppPairIconGraphic mIconGraphic;
     // A view that holds the app pair's title.
@@ -250,4 +272,14 @@ public class AppPairIcon extends FrameLayout implements DraggableView, Reorderab
         }
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
     }
+
+    @Override
+    public void onHoverChanged(boolean hovered) {
+        super.onHoverChanged(hovered);
+        ObjectAnimator
+                .ofFloat(this, HOVER_SCALE_PROPERTY,
+                        hovered ? HOVER_SCALE_MAX : HOVER_SCALE_DEFAULT)
+                .setDuration(HOVER_SCALE_DURATION)
+                .start();
+    }
 }

src/com/android/launcher3/apppairs/AppPairIconDrawable.java

@@ -26,6 +26,7 @@ import android.os.Build;
 
 import androidx.annotation.NonNull;
 
+import com.android.launcher3.Utilities;
 import com.android.launcher3.icons.FastBitmapDrawable;
 
 /**
@@ -128,6 +129,18 @@ public class AppPairIconDrawable extends Drawable {
                 height - (mP.getStandardIconPadding() + mP.getOuterPadding())
         );
 
+        // Scale each background from its center edge closest to the center channel.
+        Utilities.scaleRectFAboutPivot(
+                leftSide,
+                leftSide.left + leftSide.width(),
+                leftSide.top + leftSide.centerY(),
+                mP.getHoverScale());
+        Utilities.scaleRectFAboutPivot(
+                rightSide,
+                rightSide.left,
+                rightSide.top + rightSide.centerY(),
+                mP.getHoverScale());
+
         drawCustomRoundedRect(canvas, leftSide, new float[]{
                 mP.getBigRadius(), mP.getBigRadius(),
                 mP.getSmallRadius(), mP.getSmallRadius(),
@@ -163,6 +176,18 @@ public class AppPairIconDrawable extends Drawable {
                 height - (mP.getStandardIconPadding() + mP.getOuterPadding())
         );
 
+        // Scale each background from its center edge closest to the center channel.
+        Utilities.scaleRectFAboutPivot(
+                topSide,
+                topSide.left + topSide.centerX(),
+                topSide.top + topSide.height(),
+                mP.getHoverScale());
+        Utilities.scaleRectFAboutPivot(
+                bottomSide,
+                bottomSide.left + bottomSide.centerX(),
+                bottomSide.top,
+                mP.getHoverScale());
+
         drawCustomRoundedRect(canvas, topSide, new float[]{
                 mP.getBigRadius(), mP.getBigRadius(),
                 mP.getBigRadius(), mP.getBigRadius(),

src/com/android/launcher3/apppairs/AppPairIconDrawingParams.kt

@@ -64,6 +64,8 @@ class AppPairIconDrawingParams(val context: Context, container: Int) {
     var isLeftRightSplit: Boolean = true
     // The background paint color (based on container).
     var bgColor: Int = 0
+    // The scale of the icon background while hovered.
+    var hoverScale: Float = 1f
 
     init {
         val activity: ActivityContext = ActivityContext.lookupContext(context)

src/com/android/launcher3/apppairs/AppPairIconGraphic.kt

@@ -139,4 +139,19 @@ constructor(context: Context, attrs: AttributeSet? = null) :
         super.dispatchDraw(canvas)
         drawable.draw(canvas)
     }
+
+    /**
+     * Sets the scale of the icon background while hovered.
+     */
+    fun setHoverScale(scale: Float) {
+        drawParams.hoverScale = scale
+        redraw()
+    }
+
+    /**
+     * Gets the scale of the icon background while hovered.
+     */
+    fun getHoverScale(): Float {
+        return drawParams.hoverScale
+    }
 }