1 /*
2  * Copyright (C) 2007 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.tests.libwithcustom;
18 
19 // Need the following import to get access to the app resources, since this
20 // class is in a sub-package.
21 import android.content.Context;
22 import android.content.res.TypedArray;
23 import android.graphics.Canvas;
24 import android.graphics.Paint;
25 import android.util.AttributeSet;
26 import android.view.View;
27 
28 
29 /**
30  * Example of how to write a custom subclass of View. LabelView
31  * is used to draw simple text views. Note that it does not handle
32  * styled text or right-to-left writing systems.
33  *
34  */
35 public class LabelView extends View {
36     private Paint mTextPaint;
37     private String mText;
38     private int mAscent;
39 
40     /**
41      * Constructor.  This version is only needed if you will be instantiating
42      * the object manually (not from a layout XML file).
43      * @param context
44      */
LabelView(Context context)45     public LabelView(Context context) {
46         super(context);
47         initLabelView();
48     }
49 
50     /**
51      * Construct object, initializing with any attributes we understand from a
52      * layout file. These attributes are defined in
53      * SDK/assets/res/any/classes.xml.
54      *
55      * @see android.view.View#View(android.content.Context, android.util.AttributeSet)
56      */
LabelView(Context context, AttributeSet attrs)57     public LabelView(Context context, AttributeSet attrs) {
58         super(context, attrs);
59         initLabelView();
60 
61 
62         TypedArray a = context.obtainStyledAttributes(attrs,
63                 R.styleable.LabelView);
64 
65         CharSequence s = a.getString(R.styleable.LabelView_text);
66         if (s != null) {
67             setText(s.toString());
68         }
69 
70         // Retrieve the color(s) to be used for this view and apply them.
71         // Note, if you only care about supporting a single color, that you
72         // can instead call a.getColor() and pass that to setTextColor().
73         setTextColor(a.getColor(R.styleable.LabelView_textColor, 0xFF000000));
74 
75         int textSize = a.getDimensionPixelOffset(R.styleable.LabelView_textSize, 0);
76         if (textSize > 0) {
77             setTextSize(textSize);
78         }
79 
80         a.recycle();
81     }
82 
initLabelView()83     private final void initLabelView() {
84         mTextPaint = new Paint();
85         mTextPaint.setAntiAlias(true);
86         // Must manually scale the desired text size to match screen density
87         mTextPaint.setTextSize(16 * getResources().getDisplayMetrics().density);
88         mTextPaint.setColor(0xFF000000);
89         setPadding(3, 3, 3, 3);
90     }
91 
92     /**
93      * Sets the text to display in this label
94      * @param text The text to display. This will be drawn as one line.
95      */
setText(String text)96     public void setText(String text) {
97         mText = text;
98         requestLayout();
99         invalidate();
100     }
101 
102     /**
103      * Sets the text size for this label
104      * @param size Font size
105      */
setTextSize(int size)106     public void setTextSize(int size) {
107         // This text size has been pre-scaled by the getDimensionPixelOffset method
108         mTextPaint.setTextSize(size);
109         requestLayout();
110         invalidate();
111     }
112 
113     /**
114      * Sets the text color for this label.
115      * @param color ARGB value for the text
116      */
setTextColor(int color)117     public void setTextColor(int color) {
118         mTextPaint.setColor(color);
119         invalidate();
120     }
121 
122     /**
123      * @see android.view.View#measure(int, int)
124      */
125     @Override
onMeasure(int widthMeasureSpec, int heightMeasureSpec)126     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
127         setMeasuredDimension(measureWidth(widthMeasureSpec),
128                 measureHeight(heightMeasureSpec));
129     }
130 
131     /**
132      * Determines the width of this view
133      * @param measureSpec A measureSpec packed into an int
134      * @return The width of the view, honoring constraints from measureSpec
135      */
measureWidth(int measureSpec)136     private int measureWidth(int measureSpec) {
137         int result = 0;
138         int specMode = MeasureSpec.getMode(measureSpec);
139         int specSize = MeasureSpec.getSize(measureSpec);
140 
141         if (specMode == MeasureSpec.EXACTLY) {
142             // We were told how big to be
143             result = specSize;
144         } else {
145             // Measure the text
146             result = (int) mTextPaint.measureText(mText) + getPaddingLeft()
147                     + getPaddingRight();
148             if (specMode == MeasureSpec.AT_MOST) {
149                 // Respect AT_MOST value if that was what is called for by measureSpec
150                 result = Math.min(result, specSize);
151             }
152         }
153 
154         return result;
155     }
156 
157     /**
158      * Determines the height of this view
159      * @param measureSpec A measureSpec packed into an int
160      * @return The height of the view, honoring constraints from measureSpec
161      */
measureHeight(int measureSpec)162     private int measureHeight(int measureSpec) {
163         int result = 0;
164         int specMode = MeasureSpec.getMode(measureSpec);
165         int specSize = MeasureSpec.getSize(measureSpec);
166 
167         mAscent = (int) mTextPaint.ascent();
168         if (specMode == MeasureSpec.EXACTLY) {
169             // We were told how big to be
170             result = specSize;
171         } else {
172             // Measure the text (beware: ascent is a negative number)
173             result = (int) (-mAscent + mTextPaint.descent()) + getPaddingTop()
174                     + getPaddingBottom();
175             if (specMode == MeasureSpec.AT_MOST) {
176                 // Respect AT_MOST value if that was what is called for by measureSpec
177                 result = Math.min(result, specSize);
178             }
179         }
180         return result;
181     }
182 
183     /**
184      * Render the text
185      *
186      * @see android.view.View#onDraw(android.graphics.Canvas)
187      */
188     @Override
onDraw(Canvas canvas)189     protected void onDraw(Canvas canvas) {
190         super.onDraw(canvas);
191         canvas.drawText(mText, getPaddingLeft(), getPaddingTop() - mAscent, mTextPaint);
192     }
193 }
194