1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.support.design.internal;
18
19import static android.support.annotation.RestrictTo.Scope.LIBRARY_GROUP;
20
21import android.content.Context;
22import android.content.res.TypedArray;
23import android.graphics.Canvas;
24import android.graphics.Rect;
25import android.graphics.drawable.Drawable;
26import android.support.annotation.NonNull;
27import android.support.annotation.RequiresApi;
28import android.support.annotation.RestrictTo;
29import android.support.design.R;
30import android.support.v7.widget.LinearLayoutCompat;
31import android.util.AttributeSet;
32import android.view.Gravity;
33
34/**
35 * @hide
36 */
37@RestrictTo(LIBRARY_GROUP)
38public class ForegroundLinearLayout extends LinearLayoutCompat {
39
40    private Drawable mForeground;
41
42    private final Rect mSelfBounds = new Rect();
43
44    private final Rect mOverlayBounds = new Rect();
45
46    private int mForegroundGravity = Gravity.FILL;
47
48    protected boolean mForegroundInPadding = true;
49
50    boolean mForegroundBoundsChanged = false;
51
52    public ForegroundLinearLayout(Context context) {
53        this(context, null);
54    }
55
56    public ForegroundLinearLayout(Context context, AttributeSet attrs) {
57        this(context, attrs, 0);
58    }
59
60    public ForegroundLinearLayout(Context context, AttributeSet attrs, int defStyle) {
61        super(context, attrs, defStyle);
62
63        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ForegroundLinearLayout,
64                defStyle, 0);
65
66        mForegroundGravity = a.getInt(
67                R.styleable.ForegroundLinearLayout_android_foregroundGravity, mForegroundGravity);
68
69        final Drawable d = a.getDrawable(R.styleable.ForegroundLinearLayout_android_foreground);
70        if (d != null) {
71            setForeground(d);
72        }
73
74        mForegroundInPadding = a.getBoolean(
75                R.styleable.ForegroundLinearLayout_foregroundInsidePadding, true);
76
77        a.recycle();
78    }
79
80    /**
81     * Describes how the foreground is positioned.
82     *
83     * @return foreground gravity.
84     * @see #setForegroundGravity(int)
85     */
86    @Override
87    public int getForegroundGravity() {
88        return mForegroundGravity;
89    }
90
91    /**
92     * Describes how the foreground is positioned. Defaults to START and TOP.
93     *
94     * @param foregroundGravity See {@link android.view.Gravity}
95     * @see #getForegroundGravity()
96     */
97    @Override
98    public void setForegroundGravity(int foregroundGravity) {
99        if (mForegroundGravity != foregroundGravity) {
100            if ((foregroundGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK) == 0) {
101                foregroundGravity |= Gravity.START;
102            }
103
104            if ((foregroundGravity & Gravity.VERTICAL_GRAVITY_MASK) == 0) {
105                foregroundGravity |= Gravity.TOP;
106            }
107
108            mForegroundGravity = foregroundGravity;
109
110            if (mForegroundGravity == Gravity.FILL && mForeground != null) {
111                Rect padding = new Rect();
112                mForeground.getPadding(padding);
113            }
114
115            requestLayout();
116        }
117    }
118
119    @Override
120    protected boolean verifyDrawable(Drawable who) {
121        return super.verifyDrawable(who) || (who == mForeground);
122    }
123
124    @RequiresApi(11)
125    @Override
126    public void jumpDrawablesToCurrentState() {
127        super.jumpDrawablesToCurrentState();
128        if (mForeground != null) {
129            mForeground.jumpToCurrentState();
130        }
131    }
132
133    @Override
134    protected void drawableStateChanged() {
135        super.drawableStateChanged();
136        if (mForeground != null && mForeground.isStateful()) {
137            mForeground.setState(getDrawableState());
138        }
139    }
140
141    /**
142     * Supply a Drawable that is to be rendered on top of all of the child
143     * views in the frame layout.  Any padding in the Drawable will be taken
144     * into account by ensuring that the children are inset to be placed
145     * inside of the padding area.
146     *
147     * @param drawable The Drawable to be drawn on top of the children.
148     */
149    @Override
150    public void setForeground(Drawable drawable) {
151        if (mForeground != drawable) {
152            if (mForeground != null) {
153                mForeground.setCallback(null);
154                unscheduleDrawable(mForeground);
155            }
156
157            mForeground = drawable;
158
159            if (drawable != null) {
160                setWillNotDraw(false);
161                drawable.setCallback(this);
162                if (drawable.isStateful()) {
163                    drawable.setState(getDrawableState());
164                }
165                if (mForegroundGravity == Gravity.FILL) {
166                    Rect padding = new Rect();
167                    drawable.getPadding(padding);
168                }
169            } else {
170                setWillNotDraw(true);
171            }
172            requestLayout();
173            invalidate();
174        }
175    }
176
177    /**
178     * Returns the drawable used as the foreground of this FrameLayout. The
179     * foreground drawable, if non-null, is always drawn on top of the children.
180     *
181     * @return A Drawable or null if no foreground was set.
182     */
183    @Override
184    public Drawable getForeground() {
185        return mForeground;
186    }
187
188    @Override
189    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
190        super.onLayout(changed, left, top, right, bottom);
191        mForegroundBoundsChanged |= changed;
192    }
193
194    @Override
195    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
196        super.onSizeChanged(w, h, oldw, oldh);
197        mForegroundBoundsChanged = true;
198    }
199
200    @Override
201    public void draw(@NonNull Canvas canvas) {
202        super.draw(canvas);
203
204        if (mForeground != null) {
205            final Drawable foreground = mForeground;
206
207            if (mForegroundBoundsChanged) {
208                mForegroundBoundsChanged = false;
209                final Rect selfBounds = mSelfBounds;
210                final Rect overlayBounds = mOverlayBounds;
211
212                final int w = getRight() - getLeft();
213                final int h = getBottom() - getTop();
214
215                if (mForegroundInPadding) {
216                    selfBounds.set(0, 0, w, h);
217                } else {
218                    selfBounds.set(getPaddingLeft(), getPaddingTop(),
219                            w - getPaddingRight(), h - getPaddingBottom());
220                }
221
222                Gravity.apply(mForegroundGravity, foreground.getIntrinsicWidth(),
223                        foreground.getIntrinsicHeight(), selfBounds, overlayBounds);
224                foreground.setBounds(overlayBounds);
225            }
226
227            foreground.draw(canvas);
228        }
229    }
230
231    @RequiresApi(21)
232    @Override
233    public void drawableHotspotChanged(float x, float y) {
234        super.drawableHotspotChanged(x, y);
235        if (mForeground != null) {
236            mForeground.setHotspot(x, y);
237        }
238    }
239
240}
241