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 com.android.setupwizardlib.view;
18
19import android.annotation.TargetApi;
20import android.content.Context;
21import android.content.pm.ApplicationInfo;
22import android.content.res.TypedArray;
23import android.graphics.Canvas;
24import android.graphics.Rect;
25import android.graphics.drawable.Drawable;
26import android.os.Build.VERSION;
27import android.os.Build.VERSION_CODES;
28import android.util.AttributeSet;
29import android.util.LayoutDirection;
30import android.view.Gravity;
31import android.view.ViewOutlineProvider;
32import android.widget.FrameLayout;
33
34import com.android.setupwizardlib.R;
35
36/**
37 * Class to draw the illustration of setup wizard. The {@code aspectRatio} attribute determines the
38 * aspect ratio of the top padding, which leaves space for the illustration. Draws the illustration
39 * drawable to fit the width of the view and fills the rest with the background.
40 *
41 * <p>If an aspect ratio is set, then the aspect ratio of the source drawable is maintained.
42 * Otherwise the the aspect ratio will be ignored, only increasing the width of the illustration.
43 */
44public class Illustration extends FrameLayout {
45
46    // Size of the baseline grid in pixels
47    private float mBaselineGridSize;
48    private Drawable mBackground;
49    private Drawable mIllustration;
50    private final Rect mViewBounds = new Rect();
51    private final Rect mIllustrationBounds = new Rect();
52    private float mScale = 1.0f;
53    private float mAspectRatio = 0.0f;
54
55    public Illustration(Context context) {
56        super(context);
57        init(null, 0);
58    }
59
60    public Illustration(Context context, AttributeSet attrs) {
61        super(context, attrs);
62        init(attrs, 0);
63    }
64
65    @TargetApi(VERSION_CODES.HONEYCOMB)
66    public Illustration(Context context, AttributeSet attrs, int defStyleAttr) {
67        super(context, attrs, defStyleAttr);
68        init(attrs, defStyleAttr);
69    }
70
71    // All the constructors delegate to this init method. The 3-argument constructor is not
72    // available in FrameLayout before v11, so call super with the exact same arguments.
73    private void init(AttributeSet attrs, int defStyleAttr) {
74        if (attrs != null) {
75            TypedArray a = getContext().obtainStyledAttributes(attrs,
76                    R.styleable.SuwIllustration, defStyleAttr, 0);
77            mAspectRatio = a.getFloat(R.styleable.SuwIllustration_suwAspectRatio, 0.0f);
78            a.recycle();
79        }
80        // Number of pixels of the 8dp baseline grid as defined in material design specs
81        mBaselineGridSize = getResources().getDisplayMetrics().density * 8;
82        setWillNotDraw(false);
83    }
84
85    /**
86     * The background will be drawn to fill up the rest of the view. It will also be scaled by the
87     * same amount as the foreground so their textures look the same.
88     */
89    // Override the deprecated setBackgroundDrawable method to support API < 16. View.setBackground
90    // forwards to setBackgroundDrawable in the framework implementation.
91    @SuppressWarnings("deprecation")
92    @Override
93    public void setBackgroundDrawable(Drawable background) {
94        if (background == mBackground) {
95            return;
96        }
97        mBackground = background;
98        invalidate();
99        requestLayout();
100    }
101
102    /**
103     * Sets the drawable used as the illustration. The drawable is expected to have intrinsic
104     * width and height defined and will be scaled to fit the width of the view.
105     */
106    public void setIllustration(Drawable illustration) {
107        if (illustration == mIllustration) {
108            return;
109        }
110        mIllustration = illustration;
111        invalidate();
112        requestLayout();
113    }
114
115    /**
116     * Set the aspect ratio reserved for the illustration. This overrides the top padding of the
117     * view according to the width of this view and the aspect ratio. Children views will start
118     * being laid out below this aspect ratio.
119     *
120     * @param aspectRatio A float value specifying the aspect ratio (= width / height). 0 to not
121     *                    override the top padding.
122     */
123    public void setAspectRatio(float aspectRatio) {
124        mAspectRatio = aspectRatio;
125        invalidate();
126        requestLayout();
127    }
128
129    @Override
130    @Deprecated
131    public void setForeground(Drawable d) {
132        setIllustration(d);
133    }
134
135    @Override
136    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
137        if (mAspectRatio != 0.0f) {
138            int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
139            int illustrationHeight = (int) (parentWidth / mAspectRatio);
140            illustrationHeight -= illustrationHeight % mBaselineGridSize;
141            setPadding(0, illustrationHeight, 0, 0);
142        }
143        if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
144            //noinspection AndroidLintInlinedApi
145            setOutlineProvider(ViewOutlineProvider.BOUNDS);
146        }
147        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
148    }
149
150    @Override
151    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
152        final int layoutWidth = right - left;
153        final int layoutHeight = bottom - top;
154        if (mIllustration != null) {
155            int intrinsicWidth = mIllustration.getIntrinsicWidth();
156            int intrinsicHeight = mIllustration.getIntrinsicHeight();
157
158            mViewBounds.set(0, 0, layoutWidth, layoutHeight);
159            if (mAspectRatio != 0f) {
160                mScale = layoutWidth / (float) intrinsicWidth;
161                intrinsicWidth = layoutWidth;
162                intrinsicHeight = (int) (intrinsicHeight * mScale);
163            }
164            Gravity.apply(Gravity.FILL_HORIZONTAL | Gravity.TOP, intrinsicWidth,
165                    intrinsicHeight, mViewBounds, mIllustrationBounds);
166            mIllustration.setBounds(mIllustrationBounds);
167        }
168        if (mBackground != null) {
169            // Scale the background bounds by the same scale to compensate for the scale done to the
170            // canvas in onDraw.
171            mBackground.setBounds(0, 0, (int) Math.ceil(layoutWidth / mScale),
172                    (int) Math.ceil((layoutHeight - mIllustrationBounds.height()) / mScale));
173        }
174        super.onLayout(changed, left, top, right, bottom);
175    }
176
177    @Override
178    public void onDraw(Canvas canvas) {
179        if (mBackground != null) {
180            // Draw the background filling parts not covered by the illustration
181            canvas.save();
182            canvas.translate(0, mIllustrationBounds.height());
183            // Scale the background so its size matches the foreground
184            canvas.scale(mScale, mScale, 0, 0);
185            if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN_MR1 &&
186                    shouldMirrorDrawable(mBackground, getLayoutDirection())) {
187                // Flip the illustration for RTL layouts
188                canvas.scale(-1, 1);
189                canvas.translate(-mBackground.getBounds().width(), 0);
190            }
191            mBackground.draw(canvas);
192            canvas.restore();
193        }
194        if (mIllustration != null) {
195            canvas.save();
196            if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN_MR1 &&
197                    shouldMirrorDrawable(mIllustration, getLayoutDirection())) {
198                // Flip the illustration for RTL layouts
199                canvas.scale(-1, 1);
200                canvas.translate(-mIllustrationBounds.width(), 0);
201            }
202            // Draw the illustration
203            mIllustration.draw(canvas);
204            canvas.restore();
205        }
206        super.onDraw(canvas);
207    }
208
209    private boolean shouldMirrorDrawable(Drawable drawable, int layoutDirection) {
210        if (layoutDirection == LayoutDirection.RTL) {
211            if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {
212                return drawable.isAutoMirrored();
213            } else if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN_MR1) {
214                final int flags = getContext().getApplicationInfo().flags;
215                //noinspection AndroidLintInlinedApi
216                return (flags & ApplicationInfo.FLAG_SUPPORTS_RTL) != 0;
217            }
218        }
219        return false;
220    }
221}
222