/*
* Copyright (C) 2006 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.text;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.text.style.ParagraphStyle;
import android.util.FloatMath;
/**
* A BoringLayout is a very simple Layout implementation for text that
* fits on a single line and is all left-to-right characters.
* You will probably never want to make one of these yourself;
* if you do, be sure to call {@link #isBoring} first to make sure
* the text meets the criteria.
* <p>This class is used by widgets to control text layout. You should not need
* to use this class directly unless you are implementing your own widget
* or custom display object, in which case
* you are encouraged to use a Layout instead of calling
* {@link android.graphics.Canvas#drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint)
* Canvas.drawText()} directly.</p>
*/
public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback {
public static BoringLayout make(CharSequence source,
TextPaint paint, int outerwidth,
Alignment align,
float spacingmult, float spacingadd,
BoringLayout.Metrics metrics, boolean includepad) {
return new BoringLayout(source, paint, outerwidth, align,
spacingmult, spacingadd, metrics,
includepad);
}
public static BoringLayout make(CharSequence source,
TextPaint paint, int outerwidth,
Alignment align,
float spacingmult, float spacingadd,
BoringLayout.Metrics metrics, boolean includepad,
TextUtils.TruncateAt ellipsize, int ellipsizedWidth) {
return new BoringLayout(source, paint, outerwidth, align,
spacingmult, spacingadd, metrics,
includepad, ellipsize, ellipsizedWidth);
}
/**
* Returns a BoringLayout for the specified text, potentially reusing
* this one if it is already suitable. The caller must make sure that
* no one is still using this Layout.
*/
public BoringLayout replaceOrMake(CharSequence source, TextPaint paint,
int outerwidth, Alignment align,
float spacingmult, float spacingadd,
BoringLayout.Metrics metrics,
boolean includepad) {
replaceWith(source, paint, outerwidth, align, spacingmult,
spacingadd);
mEllipsizedWidth = outerwidth;
mEllipsizedStart = 0;
mEllipsizedCount = 0;
init(source, paint, outerwidth, align, spacingmult, spacingadd,
metrics, includepad, true);
return this;
}
/**
* Returns a BoringLayout for the specified text, potentially reusing
* this one if it is already suitable. The caller must make sure that
* no one is still using this Layout.
*/
public BoringLayout replaceOrMake(CharSequence source, TextPaint paint,
int outerwidth, Alignment align,
float spacingmult, float spacingadd,
BoringLayout.Metrics metrics,
boolean includepad,
TextUtils.TruncateAt ellipsize,
int ellipsizedWidth) {
boolean trust;
if (ellipsize == null || ellipsize == TextUtils.TruncateAt.MARQUEE) {
replaceWith(source, paint, outerwidth, align, spacingmult,
spacingadd);
mEllipsizedWidth = outerwidth;
mEllipsizedStart = 0;
mEllipsizedCount = 0;
trust = true;
} else {
replaceWith(TextUtils.ellipsize(source, paint, ellipsizedWidth,
ellipsize, true, this),
paint, outerwidth, align, spacingmult,
spacingadd);
mEllipsizedWidth = ellipsizedWidth;
trust = false;
}
init(getText(), paint, outerwidth, align, spacingmult, spacingadd,
metrics, includepad, trust);
return this;
}
public BoringLayout(CharSequence source,
TextPaint paint, int outerwidth,
Alignment align,
float spacingmult, float spacingadd,
BoringLayout.Metrics metrics, boolean includepad) {
super(source, paint, outerwidth, align, spacingmult, spacingadd);
mEllipsizedWidth = outerwidth;
mEllipsizedStart = 0;
mEllipsizedCount = 0;
init(source, paint, outerwidth, align, spacingmult, spacingadd,
metrics, includepad, true);
}
public BoringLayout(CharSequence source,
TextPaint paint, int outerwidth,
Alignment align,
float spacingmult, float spacingadd,
BoringLayout.Metrics metrics, boolean includepad,
TextUtils.TruncateAt ellipsize, int ellipsizedWidth) {
/*
* It is silly to have to call super() and then replaceWith(),
* but we can't use "this" for the callback until the call to
* super() finishes.
*/
super(source, paint, outerwidth, align, spacingmult, spacingadd);
boolean trust;
if (ellipsize == null || ellipsize == TextUtils.TruncateAt.MARQUEE) {
mEllipsizedWidth = outerwidth;
mEllipsizedStart = 0;
mEllipsizedCount = 0;
trust = true;
} else {
replaceWith(TextUtils.ellipsize(source, paint, ellipsizedWidth,
ellipsize, true, this),
paint, outerwidth, align, spacingmult,
spacingadd);
mEllipsizedWidth = ellipsizedWidth;
trust = false;
}
init(getText(), paint, outerwidth, align, spacingmult, spacingadd,
metrics, includepad, trust);
}
/* package */ void init(CharSequence source,
TextPaint paint, int outerwidth,
Alignment align,
float spacingmult, float spacingadd,
BoringLayout.Metrics metrics, boolean includepad,
boolean trustWidth) {
int spacing;
if (source instanceof String && align == Layout.Alignment.ALIGN_NORMAL) {
mDirect = source.toString();
} else {
mDirect = null;
}
mPaint = paint;
if (includepad) {
spacing = metrics.bottom - metrics.top;
} else {
spacing = metrics.descent - metrics.ascent;
}
mBottom = spacing;
if (includepad) {
mDesc = spacing + metrics.top;
} else {
mDesc = spacing + metrics.ascent;
}
if (trustWidth) {
mMax = metrics.width;
} else {
/*
* If we have ellipsized, we have to actually calculate the
* width because the width that was passed in was for the
* full text, not the ellipsized form.
*/
TextLine line = TextLine.obtain();
line.set(paint, source, 0, source.length(), Layout.DIR_LEFT_TO_RIGHT,
Layout.DIRS_ALL_LEFT_TO_RIGHT, false, null);
mMax = (int) FloatMath.ceil(line.metrics(null));
TextLine.recycle(line);
}
if (includepad) {
mTopPadding = metrics.top - metrics.ascent;
mBottomPadding = metrics.bottom - metrics.descent;
}
}
/**
* Returns null if not boring; the width, ascent, and descent if boring.
*/
public static Metrics isBoring(CharSequence text,
TextPaint paint) {
return isBoring(text, paint, TextDirectionHeuristics.FIRSTSTRONG_LTR, null);
}
/**
* Returns null if not boring; the width, ascent, and descent if boring.
* @hide
*/
public static Metrics isBoring(CharSequence text,
TextPaint paint,
TextDirectionHeuristic textDir) {
return isBoring(text, paint, textDir, null);
}
/**
* Returns null if not boring; the width, ascent, and descent in the
* provided Metrics object (or a new one if the provided one was null)
* if boring.
*/
public static Metrics isBoring(CharSequence text, TextPaint paint, Metrics metrics) {
return isBoring(text, paint, TextDirectionHeuristics.FIRSTSTRONG_LTR, metrics);
}
/**
* Returns null if not boring; the width, ascent, and descent in the
* provided Metrics object (or a new one if the provided one was null)
* if boring.
* @hide
*/
public static Metrics isBoring(CharSequence text, TextPaint paint,
TextDirectionHeuristic textDir, Metrics metrics) {
char[] temp = TextUtils.obtain(500);
int length = text.length();
boolean boring = true;
outer:
for (int i = 0; i < length; i += 500) {
int j = i + 500;
if (j > length)
j = length;
TextUtils.getChars(text, i, j, temp, 0);
int n = j - i;
for (int a = 0; a < n; a++) {
char c = temp[a];
if (c == '\n' || c == '\t' || c >= FIRST_RIGHT_TO_LEFT) {
boring = false;
break outer;
}
}
if (textDir != null && textDir.isRtl(temp, 0, n)) {
boring = false;
break outer;
}
}
TextUtils.recycle(temp);
if (boring && text instanceof Spanned) {
Spanned sp = (Spanned) text;
Object[] styles = sp.getSpans(0, length, ParagraphStyle.class);
if (styles.length > 0) {
boring = false;
}
}
if (boring) {
Metrics fm = metrics;
if (fm == null) {
fm = new Metrics();
}
TextLine line = TextLine.obtain();
line.set(paint, text, 0, length, Layout.DIR_LEFT_TO_RIGHT,
Layout.DIRS_ALL_LEFT_TO_RIGHT, false, null);
fm.width = (int) FloatMath.ceil(line.metrics(fm));
TextLine.recycle(line);
return fm;
} else {
return null;
}
}
@Override
public int getHeight() {
return mBottom;
}
@Override
public int getLineCount() {
return 1;
}
@Override
public int getLineTop(int line) {
if (line == 0)
return 0;
else
return mBottom;
}
@Override
public int getLineDescent(int line) {
return mDesc;
}
@Override
public int getLineStart(int line) {
if (line == 0)
return 0;
else
return getText().length();
}
@Override
public int getParagraphDirection(int line) {
return DIR_LEFT_TO_RIGHT;
}
@Override
public boolean getLineContainsTab(int line) {
return false;
}
@Override
public float getLineMax(int line) {
return mMax;
}
@Override
public final Directions getLineDirections(int line) {
return Layout.DIRS_ALL_LEFT_TO_RIGHT;
}
@Override
public int getTopPadding() {
return mTopPadding;
}
@Override
public int getBottomPadding() {
return mBottomPadding;
}
@Override
public int getEllipsisCount(int line) {
return mEllipsizedCount;
}
@Override
public int getEllipsisStart(int line) {
return mEllipsizedStart;
}
@Override
public int getEllipsizedWidth() {
return mEllipsizedWidth;
}
// Override draw so it will be faster.
@Override
public void draw(Canvas c, Path highlight, Paint highlightpaint,
int cursorOffset) {
if (mDirect != null && highlight == null) {
c.drawText(mDirect, 0, mBottom - mDesc, mPaint);
} else {
super.draw(c, highlight, highlightpaint, cursorOffset);
}
}
/**
* Callback for the ellipsizer to report what region it ellipsized.
*/
public void ellipsized(int start, int end) {
mEllipsizedStart = start;
mEllipsizedCount = end - start;
}
private static final char FIRST_RIGHT_TO_LEFT = '\u0590';
private String mDirect;
private Paint mPaint;
/* package */ int mBottom, mDesc; // for Direct
private int mTopPadding, mBottomPadding;
private float mMax;
private int mEllipsizedWidth, mEllipsizedStart, mEllipsizedCount;
private static final TextPaint sTemp =
new TextPaint();
public static class Metrics extends Paint.FontMetricsInt {
public int width;
@Override public String toString() {
return super.toString() + " width=" + width;
}
}
}
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