MaterialCardView add ripple drawable to foreground

PiperOrigin-RevId: 208993686
material-components · Aug 17, 2018 · 09673a5 · 09673a5 · danielesegato · Oct 3, 2018
1 parent 43bdfac
commit 09673a5
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Showing 2 changed files with 61 additions and 6 deletions.
diff --git a/lib/java/com/google/android/material/card/MaterialCardView.java b/lib/java/com/google/android/material/card/MaterialCardView.java
@@ -152,6 +152,12 @@ public void setLayoutParams(ViewGroup.LayoutParams params) {
     }
   }
 
+  @Override
+  public void setClickable(boolean clickable) {
+    super.setClickable(clickable);
+    cardViewHelper.updateForeground();
+  }
+
   @Override
   public void addView(View child, int index, ViewGroup.LayoutParams params) {
     contentLayout.addView(child, index, params);

diff --git a/lib/java/com/google/android/material/card/MaterialCardViewHelper.java b/lib/java/com/google/android/material/card/MaterialCardViewHelper.java
@@ -21,27 +21,40 @@
 import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;
 
 import android.annotation.TargetApi;
+import android.content.Context;
+import android.content.res.ColorStateList;
 import android.content.res.TypedArray;
 import android.graphics.Outline;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.GradientDrawable;
+import android.graphics.drawable.LayerDrawable;
+import android.graphics.drawable.RippleDrawable;
+import android.graphics.drawable.ShapeDrawable;
+import android.graphics.drawable.StateListDrawable;
+import android.graphics.drawable.shapes.RoundRectShape;
 import android.os.Build.VERSION_CODES;
 import android.support.annotation.ColorInt;
 import android.support.annotation.Dimension;
 import android.support.annotation.Nullable;
 import android.support.annotation.RestrictTo;
+import com.google.android.material.ripple.RippleUtils;
+import android.support.v4.graphics.drawable.DrawableCompat;
+import android.util.TypedValue;
 import android.view.View;
 import android.view.ViewOutlineProvider;
+import java.util.Arrays;
 
 /** @hide */
 @RestrictTo(LIBRARY_GROUP)
 class MaterialCardViewHelper {
 
   private static final int DEFAULT_STROKE_VALUE = -1;
+
   private final MaterialCardView materialCardView;
 
-  private int strokeColor;
-  private int strokeWidth;
+  private @ColorInt int strokeColor;
+  private @ColorInt int rippleColor;
+  private @Dimension int strokeWidth;
 
   public MaterialCardViewHelper(MaterialCardView card) {
     materialCardView = card;
@@ -51,7 +64,7 @@ public void loadFromAttributes(TypedArray attributes) {
     strokeColor =
         attributes.getColor(R.styleable.MaterialCardView_strokeColor, DEFAULT_STROKE_VALUE);
     strokeWidth = attributes.getDimensionPixelSize(R.styleable.MaterialCardView_strokeWidth, 0);
-
+    rippleColor = getRippleColor();
     updateForeground();
     adjustContentPadding();
   }
@@ -61,7 +74,6 @@ void setStrokeColor(@ColorInt int strokeColor) {
     updateForeground();
   }
 
-
   @TargetApi(VERSION_CODES.LOLLIPOP)
   void createOutlineProvider(@Nullable View contentView) {
     if (contentView == null) {
@@ -116,7 +128,8 @@ void updateForeground() {
    */
   private Drawable createForegroundDrawable() {
     GradientDrawable fgDrawable = new GradientDrawable();
-    fgDrawable.setCornerRadius(materialCardView.getRadius());
+    float radius = materialCardView.getRadius();
+    fgDrawable.setCornerRadius(radius);
 
     // In order to set a stroke, a size and color both need to be set. We default to a zero-width
     // width size, but won't set a default color. This prevents drawing a stroke that blends in with
@@ -125,7 +138,28 @@ private Drawable createForegroundDrawable() {
       fgDrawable.setStroke(strokeWidth, strokeColor);
     }
 
-    return fgDrawable;
+    if (!materialCardView.isClickable()) {
+      return fgDrawable;
+    }
+
+    Drawable rippleDrawable;
+    if (RippleUtils.USE_FRAMEWORK_RIPPLE) {
+      //noinspection NewApi
+      rippleDrawable =
+          new RippleDrawable(
+              ColorStateList.valueOf(rippleColor), null, createForegroundShape(radius));
+    } else {
+      rippleDrawable = new StateListDrawable();
+      Drawable foregroundShape = createForegroundShape(radius);
+      DrawableCompat.setTint(foregroundShape, rippleColor);
+      ((StateListDrawable) rippleDrawable)
+          .addState(new int[] {android.R.attr.state_pressed}, foregroundShape);
+    }
+
+    return new LayerDrawable(
+        new Drawable[] {
+          rippleDrawable, fgDrawable,
+        });
   }
 
   /** Guarantee at least enough content padding to account for the stroke width. */
@@ -137,4 +171,19 @@ private void adjustContentPadding() {
     materialCardView.setContentPadding(
         contentPaddingLeft, contentPaddingTop, contentPaddingRight, contentPaddingBottom);
   }
+
+  private int getRippleColor() {
+    Context context = materialCardView.getContext();
+    TypedValue value = new TypedValue();
+    context.getTheme().resolveAttribute(R.attr.colorControlHighlight, value, true);
+    return value.data;
+  }
+
+  private Drawable createForegroundShape(float radius) {
+    float[] radii = new float[8];
+    Arrays.fill(radii, radius);
+    RoundRectShape shape = new RoundRectShape(radii, null, null);
+    ShapeDrawable shapeDrawable = new ShapeDrawable(shape);
+    return shapeDrawable;
+  }
 }