ImageFloatingTextView.java revision 4fefed2b5ee5cb8e473be2e36743bbc93a3d7a27 
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.internal.widget;
18
19import android.annotation.Nullable;
20import android.content.Context;
21import android.text.BoringLayout;
22import android.text.Layout;
23import android.text.StaticLayout;
24import android.text.TextUtils;
25import android.text.method.TransformationMethod;
26import android.util.AttributeSet;
27import android.view.RemotableViewMethod;
28import android.widget.RemoteViews;
29import android.widget.TextView;
30
31/**
32 * A TextView that can float around an image on the end.
33 *
34 * @hide
35 */
36@RemoteViews.RemoteView
37public class ImageFloatingTextView extends TextView {
38
39    /** Number of lines from the top to indent */
40    private int mIndentLines;
41
42    /** Resolved layout direction */
43    private int mResolvedDirection = LAYOUT_DIRECTION_UNDEFINED;
44    private int mMaxLinesForHeight = -1;
45    private int mLayoutMaxLines = -1;
46    private int mImageEndMargin;
47
48    public ImageFloatingTextView(Context context) {
49        this(context, null);
50    }
51
52    public ImageFloatingTextView(Context context, @Nullable AttributeSet attrs) {
53        this(context, attrs, 0);
54    }
55
56    public ImageFloatingTextView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
57        this(context, attrs, defStyleAttr, 0);
58    }
59
60    public ImageFloatingTextView(Context context, AttributeSet attrs, int defStyleAttr,
61            int defStyleRes) {
62        super(context, attrs, defStyleAttr, defStyleRes);
63    }
64
65    @Override
66    protected Layout makeSingleLayout(int wantWidth, BoringLayout.Metrics boring, int ellipsisWidth,
67            Layout.Alignment alignment, boolean shouldEllipsize,
68            TextUtils.TruncateAt effectiveEllipsize, boolean useSaved) {
69        TransformationMethod transformationMethod = getTransformationMethod();
70        CharSequence text = getText();
71        if (transformationMethod != null) {
72            text = transformationMethod.getTransformation(text, this);
73        }
74        text = text == null ? "" : text;
75        StaticLayout.Builder builder = StaticLayout.Builder.obtain(text, 0, text.length(),
76                getPaint(), wantWidth)
77                .setAlignment(alignment)
78                .setTextDirection(getTextDirectionHeuristic())
79                .setLineSpacing(getLineSpacingExtra(), getLineSpacingMultiplier())
80                .setIncludePad(getIncludeFontPadding())
81                .setUseLineSpacingFromFallbacks(true)
82                .setBreakStrategy(Layout.BREAK_STRATEGY_HIGH_QUALITY)
83                .setHyphenationFrequency(Layout.HYPHENATION_FREQUENCY_FULL);
84        int maxLines;
85        if (mMaxLinesForHeight > 0) {
86            maxLines = mMaxLinesForHeight;
87        } else {
88            maxLines = getMaxLines() >= 0 ? getMaxLines() : Integer.MAX_VALUE;
89        }
90        builder.setMaxLines(maxLines);
91        mLayoutMaxLines = maxLines;
92        if (shouldEllipsize) {
93            builder.setEllipsize(effectiveEllipsize)
94                    .setEllipsizedWidth(ellipsisWidth);
95        }
96
97        // we set the endmargin on the requested number of lines.
98        int[] margins = null;
99        if (mIndentLines > 0) {
100            margins = new int[mIndentLines + 1];
101            for (int i = 0; i < mIndentLines; i++) {
102                margins[i] = mImageEndMargin;
103            }
104        }
105        if (mResolvedDirection == LAYOUT_DIRECTION_RTL) {
106            builder.setIndents(margins, null);
107        } else {
108            builder.setIndents(null, margins);
109        }
110
111        return builder.build();
112    }
113
114    @RemotableViewMethod
115    public void setImageEndMargin(int imageEndMargin) {
116        mImageEndMargin = imageEndMargin;
117    }
118
119    @Override
120    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
121        int availableHeight = MeasureSpec.getSize(heightMeasureSpec) - mPaddingTop - mPaddingBottom;
122        if (getLayout() != null && getLayout().getHeight() != availableHeight) {
123            // We've been measured before and the new size is different than before, lets make sure
124            // we reset the maximum lines, otherwise we may be cut short
125            mMaxLinesForHeight = -1;
126            nullLayouts();
127        }
128        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
129        Layout layout = getLayout();
130        if (layout.getHeight() > availableHeight) {
131            // With the existing layout, not all of our lines fit on the screen, let's find the
132            // first one that fits and ellipsize at that one.
133            int maxLines = layout.getLineCount() - 1;
134            while (maxLines > 1 && layout.getLineBottom(maxLines - 1) > availableHeight) {
135                maxLines--;
136            }
137            if (getMaxLines() > 0) {
138                maxLines = Math.min(getMaxLines(), maxLines);
139            }
140            // Only if the number of lines is different from the current layout, we recreate it.
141            if (maxLines != mLayoutMaxLines) {
142                mMaxLinesForHeight = maxLines;
143                nullLayouts();
144                super.onMeasure(widthMeasureSpec, heightMeasureSpec);
145            }
146        }
147    }
148
149    @Override
150    public void onRtlPropertiesChanged(int layoutDirection) {
151        super.onRtlPropertiesChanged(layoutDirection);
152
153        if (layoutDirection != mResolvedDirection && isLayoutDirectionResolved()) {
154            mResolvedDirection = layoutDirection;
155            if (mIndentLines > 0) {
156                // Invalidate layout.
157                nullLayouts();
158                requestLayout();
159            }
160        }
161    }
162
163    @RemotableViewMethod
164    public void setHasImage(boolean hasImage) {
165        setNumIndentLines(hasImage ? 2 : 0);
166    }
167
168    /**
169     * @param lines the number of lines at the top that should be indented by indentEnd
170     * @return whether a change was made
171     */
172    public boolean setNumIndentLines(int lines) {
173        if (mIndentLines != lines) {
174            mIndentLines = lines;
175            // Invalidate layout.
176            nullLayouts();
177            requestLayout();
178            return true;
179        }
180        return false;
181    }
182}
183