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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  
17  package com.android.setupwizardlib.view;
18  
19  import android.annotation.TargetApi;
20  import android.content.Context;
21  import android.content.pm.ApplicationInfo;
22  import android.content.res.TypedArray;
23  import android.graphics.Canvas;
24  import android.graphics.Rect;
25  import android.graphics.drawable.Drawable;
26  import android.os.Build.VERSION;
27  import android.os.Build.VERSION_CODES;
28  import android.util.AttributeSet;
29  import android.util.LayoutDirection;
30  import android.view.Gravity;
31  import android.view.ViewOutlineProvider;
32  import android.widget.FrameLayout;
33  import com.android.setupwizardlib.R;
34  
35  /**
36   * Class to draw the illustration of setup wizard. The {@code aspectRatio} attribute determines the
37   * aspect ratio of the top padding, which leaves space for the illustration. Draws the illustration
38   * drawable to fit the width of the view and fills the rest with the background.
39   *
40   * <p>If an aspect ratio is set, then the aspect ratio of the source drawable is maintained.
41   * Otherwise the aspect ratio will be ignored, only increasing the width of the illustration.
42   */
43  public class Illustration extends FrameLayout {
44  
45    // Size of the baseline grid in pixels
46    private float baselineGridSize;
47    private Drawable background;
48    private Drawable illustration;
49    private final Rect viewBounds = new Rect();
50    private final Rect illustrationBounds = new Rect();
51    private float scale = 1.0f;
52    private float aspectRatio = 0.0f;
53  
Illustration(Context context)54    public Illustration(Context context) {
55      super(context);
56      init(null, 0);
57    }
58  
Illustration(Context context, AttributeSet attrs)59    public Illustration(Context context, AttributeSet attrs) {
60      super(context, attrs);
61      init(attrs, 0);
62    }
63  
64    @TargetApi(VERSION_CODES.HONEYCOMB)
Illustration(Context context, AttributeSet attrs, int defStyleAttr)65    public Illustration(Context context, AttributeSet attrs, int defStyleAttr) {
66      super(context, attrs, defStyleAttr);
67      init(attrs, defStyleAttr);
68    }
69  
70    // All the constructors delegate to this init method. The 3-argument constructor is not
71    // available in FrameLayout before v11, so call super with the exact same arguments.
init(AttributeSet attrs, int defStyleAttr)72    private void init(AttributeSet attrs, int defStyleAttr) {
73      if (attrs != null) {
74        TypedArray a =
75            getContext().obtainStyledAttributes(attrs, R.styleable.SuwIllustration, defStyleAttr, 0);
76        aspectRatio = a.getFloat(R.styleable.SuwIllustration_suwAspectRatio, 0.0f);
77        a.recycle();
78      }
79      // Number of pixels of the 8dp baseline grid as defined in material design specs
80      baselineGridSize = getResources().getDisplayMetrics().density * 8;
81      setWillNotDraw(false);
82    }
83  
84    /**
85     * The background will be drawn to fill up the rest of the view. It will also be scaled by the
86     * same amount as the foreground so their textures look the same.
87     */
88    // Override the deprecated setBackgroundDrawable method to support API < 16. View.setBackground
89    // forwards to setBackgroundDrawable in the framework implementation.
90    @SuppressWarnings("deprecation")
91    @Override
setBackgroundDrawable(Drawable background)92    public void setBackgroundDrawable(Drawable background) {
93      if (background == this.background) {
94        return;
95      }
96      this.background = background;
97      invalidate();
98      requestLayout();
99    }
100  
101    /**
102     * Sets the drawable used as the illustration. The drawable is expected to have intrinsic width
103     * and height defined and will be scaled to fit the width of the view.
104     */
setIllustration(Drawable illustration)105    public void setIllustration(Drawable illustration) {
106      if (illustration == this.illustration) {
107        return;
108      }
109      this.illustration = illustration;
110      invalidate();
111      requestLayout();
112    }
113  
114    /**
115     * Set the aspect ratio reserved for the illustration. This overrides the top padding of the view
116     * according to the width of this view and the aspect ratio. Children views will start being laid
117     * out below this aspect ratio.
118     *
119     * @param aspectRatio A float value specifying the aspect ratio (= width / height). 0 to not
120     *     override the top padding.
121     */
setAspectRatio(float aspectRatio)122    public void setAspectRatio(float aspectRatio) {
123      this.aspectRatio = aspectRatio;
124      invalidate();
125      requestLayout();
126    }
127  
128    @Override
129    @Deprecated
setForeground(Drawable d)130    public void setForeground(Drawable d) {
131      setIllustration(d);
132    }
133  
134    @Override
onMeasure(int widthMeasureSpec, int heightMeasureSpec)135    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
136      if (aspectRatio != 0.0f) {
137        int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
138        int illustrationHeight = (int) (parentWidth / aspectRatio);
139        illustrationHeight = (int) (illustrationHeight - (illustrationHeight % baselineGridSize));
140        setPadding(0, illustrationHeight, 0, 0);
141      }
142      if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
143        //noinspection AndroidLintInlinedApi
144        setOutlineProvider(ViewOutlineProvider.BOUNDS);
145      }
146      super.onMeasure(widthMeasureSpec, heightMeasureSpec);
147    }
148  
149    @Override
onLayout(boolean changed, int left, int top, int right, int bottom)150    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
151      final int layoutWidth = right - left;
152      final int layoutHeight = bottom - top;
153      if (illustration != null) {
154        int intrinsicWidth = illustration.getIntrinsicWidth();
155        int intrinsicHeight = illustration.getIntrinsicHeight();
156  
157        viewBounds.set(0, 0, layoutWidth, layoutHeight);
158        if (aspectRatio != 0f) {
159          scale = layoutWidth / (float) intrinsicWidth;
160          intrinsicWidth = layoutWidth;
161          intrinsicHeight = (int) (intrinsicHeight * scale);
162        }
163        Gravity.apply(
164            Gravity.FILL_HORIZONTAL | Gravity.TOP,
165            intrinsicWidth,
166            intrinsicHeight,
167            viewBounds,
168            illustrationBounds);
169        illustration.setBounds(illustrationBounds);
170      }
171      if (background != null) {
172        // Scale the background bounds by the same scale to compensate for the scale done to the
173        // canvas in onDraw.
174        background.setBounds(
175            0,
176            0,
177            (int) Math.ceil(layoutWidth / scale),
178            (int) Math.ceil((layoutHeight - illustrationBounds.height()) / scale));
179      }
180      super.onLayout(changed, left, top, right, bottom);
181    }
182  
183    @Override
onDraw(Canvas canvas)184    public void onDraw(Canvas canvas) {
185      if (background != null) {
186        // Draw the background filling parts not covered by the illustration
187        canvas.save();
188        canvas.translate(0, illustrationBounds.height());
189        // Scale the background so its size matches the foreground
190        canvas.scale(scale, scale, 0, 0);
191        if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN_MR1
192            && shouldMirrorDrawable(background, getLayoutDirection())) {
193          // Flip the illustration for RTL layouts
194          canvas.scale(-1, 1);
195          canvas.translate(-background.getBounds().width(), 0);
196        }
197        background.draw(canvas);
198        canvas.restore();
199      }
200      if (illustration != null) {
201        canvas.save();
202        if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN_MR1
203            && shouldMirrorDrawable(illustration, getLayoutDirection())) {
204          // Flip the illustration for RTL layouts
205          canvas.scale(-1, 1);
206          canvas.translate(-illustrationBounds.width(), 0);
207        }
208        // Draw the illustration
209        illustration.draw(canvas);
210        canvas.restore();
211      }
212      super.onDraw(canvas);
213    }
214  
shouldMirrorDrawable(Drawable drawable, int layoutDirection)215    private boolean shouldMirrorDrawable(Drawable drawable, int layoutDirection) {
216      if (layoutDirection == LayoutDirection.RTL) {
217        if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {
218          return drawable.isAutoMirrored();
219        } else if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN_MR1) {
220          final int flags = getContext().getApplicationInfo().flags;
221          //noinspection AndroidLintInlinedApi
222          return (flags & ApplicationInfo.FLAG_SUPPORTS_RTL) != 0;
223        }
224      }
225      return false;
226    }
227  }
228