ShadowOverlayContainer.java revision 9240e796bc63422c28f2707840bd99c48573279b 
1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14package android.support.v17.leanback.widget;
15
16import android.content.Context;
17import android.support.v17.leanback.R;
18import android.util.AttributeSet;
19import android.view.LayoutInflater;
20import android.view.View;
21import android.view.ViewGroup;
22import android.widget.FrameLayout;
23
24/**
25 * ShadowOverlayContainer Provides a SDK version independent wrapper container
26 * to take care of shadow and/or color overlay.
27 * <p>
28 * Shadow and color dimmer overlay are both optional.  When shadow is used,  it's
29 * user's responsibility to properly call setClipChildren(false) on parent views if
30 * the shadow can appear outside bounds of parent views.
31 * {@link #prepareParentForShadow(ViewGroup)} must be called on parent of container
32 * before using shadow.  Depending on sdk version, optical bounds might be applied
33 * to parent.
34 * </p>
35 * <p>
36 * {@link #initialize(boolean, boolean)} must be first called on the container to initialize
37 * shadows and/or color overlay.  Then call {@link #wrap(View)} to insert wrapped view
38 * into container.
39 * </p>
40 * <p>
41 * Call {@link #setShadowFocusLevel(float)} to control shadow alpha.
42 * </p>
43 * <p>
44 * Call {@link #setOverlayColor(int)} to control overlay color.
45 * </p>
46 */
47public class ShadowOverlayContainer extends FrameLayout {
48
49    private boolean mInitialized;
50    private View mColorDimOverlay;
51    private Object mShadowImpl;
52
53    public ShadowOverlayContainer(Context context) {
54        this(context, null, 0);
55    }
56
57    public ShadowOverlayContainer(Context context, AttributeSet attrs) {
58        this(context, attrs, 0);
59    }
60
61    public ShadowOverlayContainer(Context context, AttributeSet attrs, int defStyle) {
62        super(context, attrs, defStyle);
63    }
64
65    /**
66     * Return true if the platform sdk supports shadow.
67     */
68    public static boolean supportsShadow() {
69        return ShadowHelper.getInstance().supportsShadow();
70    }
71
72    /**
73     * {@link #prepareParentForShadow(ViewGroup)} must be called on parent of container
74     * before using shadow.  Depending on sdk version, optical bounds might be applied
75     * to parent.
76     */
77    public static void prepareParentForShadow(ViewGroup parent) {
78        ShadowHelper.getInstance().prepareParent(parent);
79    }
80
81    /**
82     * Initialize shadows and/or color overlay.  Both are optional.
83     */
84    public void initialize(boolean hasShadow, boolean hasColorDimOverlay) {
85        if (mInitialized) {
86            throw new IllegalStateException();
87        }
88        mInitialized = true;
89        if (hasShadow) {
90            mShadowImpl = ShadowHelper.getInstance().addShadow(this);
91        }
92        if (hasColorDimOverlay) {
93            mColorDimOverlay = LayoutInflater.from(getContext())
94                    .inflate(R.layout.lb_card_color_overlay, this, false);
95            addView(mColorDimOverlay);
96        }
97    }
98
99    /**
100     * Set shadow focus level (0 to 1). 0 for unfocused, 1f for fully focused.
101     */
102    public void setShadowFocusLevel(float level) {
103        if (mShadowImpl != null) {
104            if (level < 0f) {
105                level = 0f;
106            } else if (level > 1f) {
107                level = 1f;
108            }
109            ShadowHelper.getInstance().setShadowFocusLevel(mShadowImpl, level);
110        }
111    }
112
113    /**
114     * Set color (with alpha) of the overlay.
115     */
116    public void setOverlayColor(int overlayColor) {
117        if (mColorDimOverlay != null) {
118            mColorDimOverlay.setBackgroundColor(overlayColor);
119        }
120    }
121
122    /**
123     * Inserts view into the wrapper.
124     */
125    public void wrap(View view) {
126        if (!mInitialized) {
127            throw new IllegalStateException();
128        }
129        if (mColorDimOverlay != null) {
130            addView(view, indexOfChild(mColorDimOverlay));
131        } else {
132            addView(view);
133        }
134    }
135
136}
137