1 files changed, 175 insertions, 0 deletions
diff --git a/src/com/android/tv/menu/BaseCardView.java b/src/com/android/tv/menu/BaseCardView.java
new file mode 100644
index 00000000..25d4e313
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+++ b/src/com/android/tv/menu/BaseCardView.java
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+package com.android.tv.menu;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.ValueAnimator;
+import android.content.Context;
+import android.graphics.Outline;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewOutlineProvider;
+import android.widget.LinearLayout;
+
+import com.android.tv.R;
+
+/**
+ * A base class to render a card.
+ */
+public abstract class BaseCardView<T> extends LinearLayout implements ItemListRowView.CardView<T> {
+    private static final String TAG = "BaseCardView";
+    private static final boolean DEBUG = false;
+
+    private static final float SCALE_FACTOR_0F = 0f;
+    private static final float SCALE_FACTOR_1F = 1f;
+
+    private ValueAnimator mFocusAnimator;
+    private final int mFocusAnimDuration;
+    private final float mFocusTranslationZ;
+    private final float mVerticalCardMargin;
+    private final float mCardCornerRadius;
+    private float mFocusAnimatedValue;
+
+    public BaseCardView(Context context) {
+        this(context, null);
+    }
+
+    public BaseCardView(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public BaseCardView(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+
+        setClipToOutline(true);
+        mFocusAnimDuration = getResources().getInteger(R.integer.menu_focus_anim_duration);
+        mFocusTranslationZ = getResources().getDimension(R.dimen.channel_card_elevation_focused)
+                - getResources().getDimension(R.dimen.card_elevation_normal);
+        mVerticalCardMargin = 2 * (
+                getResources().getDimensionPixelOffset(R.dimen.menu_list_padding_top)
+                + getResources().getDimensionPixelOffset(R.dimen.menu_list_margin_top));
+        // Ensure the same elevation and focus animation for all subclasses.
+        setElevation(getResources().getDimension(R.dimen.card_elevation_normal));
+        mCardCornerRadius = getResources().getDimensionPixelSize(R.dimen.channel_card_round_radius);
+        setOutlineProvider(new ViewOutlineProvider() {
+            @Override
+            public void getOutline(View view, Outline outline) {
+                outline.setRoundRect(0, 0, view.getWidth(), view.getHeight(), mCardCornerRadius);
+            }
+        });
+    }
+
+    /**
+     * Called when the view is displayed.
+     */
+    @Override
+    public void onBind(T item, boolean selected) {
+        // Note that getCardHeight() will be called by setFocusAnimatedValue().
+        // Therefore, be sure that getCardHeight() has a proper value before this method is called.
+       setFocusAnimatedValue(selected ? SCALE_FACTOR_1F : SCALE_FACTOR_0F);
+    }
+
+    @Override
+    public void onSelected() {
+        if (isAttachedToWindow() && getVisibility() == View.VISIBLE) {
+            startFocusAnimation(SCALE_FACTOR_1F);
+        } else {
+            cancelFocusAnimationIfAny();
+            setFocusAnimatedValue(SCALE_FACTOR_1F);
+        }
+    }
+
+    @Override
+    public void onDeselected() {
+        if (isAttachedToWindow() && getVisibility() == View.VISIBLE) {
+            startFocusAnimation(SCALE_FACTOR_0F);
+        } else {
+            cancelFocusAnimationIfAny();
+            setFocusAnimatedValue(SCALE_FACTOR_0F);
+        }
+    }
+
+    /**
+     * Called when the focus animation started.
+     */
+    protected void onFocusAnimationStart(boolean selected) {
+        // do nothing.
+    }
+
+    /**
+     * Called when the focus animation ended.
+     */
+    protected void onFocusAnimationEnd(boolean selected) {
+        // do nothing.
+    }
+
+    /**
+     * Called when the view is bound, or while focus animation is running with a value
+     * between {@code SCALE_FACTOR_0F} and {@code SCALE_FACTOR_1F}.
+     */
+    protected void onSetFocusAnimatedValue(float animatedValue) {
+        float scale = 1f + (mVerticalCardMargin / getCardHeight()) * animatedValue;
+        setScaleX(scale);
+        setScaleY(scale);
+        setTranslationZ(mFocusTranslationZ * animatedValue);
+    }
+
+    private void setFocusAnimatedValue(float animatedValue) {
+        mFocusAnimatedValue = animatedValue;
+        onSetFocusAnimatedValue(animatedValue);
+    }
+
+    private void startFocusAnimation(final float targetAnimatedValue) {
+        cancelFocusAnimationIfAny();
+        final boolean selected = targetAnimatedValue == SCALE_FACTOR_1F;
+        mFocusAnimator = ValueAnimator.ofFloat(mFocusAnimatedValue, targetAnimatedValue);
+        mFocusAnimator.setDuration(mFocusAnimDuration);
+        mFocusAnimator.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationStart(Animator animation) {
+                setHasTransientState(true);
+                onFocusAnimationStart(selected);
+            }
+
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                setHasTransientState(false);
+                onFocusAnimationEnd(selected);
+            }
+        });
+        mFocusAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
+            @Override
+            public void onAnimationUpdate(ValueAnimator animation) {
+                setFocusAnimatedValue((Float) animation.getAnimatedValue());
+            }
+        });
+        mFocusAnimator.start();
+    }
+
+    private void cancelFocusAnimationIfAny() {
+        if (mFocusAnimator != null) {
+            mFocusAnimator.cancel();
+            mFocusAnimator = null;
+        }
+    }
+
+    /**
+     * The implementation should return the height of the card.
+     */
+    protected abstract float getCardHeight();
+}