LineBreaker
open class LineBreaker
| kotlin.Any | |
| ↳ | android.graphics.text.LineBreaker |
Provides automatic line breaking for a single paragraph.
<code>
Paint paint = new Paint();
Paint bigPaint = new Paint();
bigPaint.setTextSize(paint.getTextSize() * 2.0);
String text = "Hello, Android.";
// Prepare the measured text
MeasuredText mt = new MeasuredText.Builder(text.toCharArray())
.appendStyleRun(paint, 7, false) // Use paint for "Hello, "
.appednStyleRun(bigPaint, 8, false) // Use bigPaint for "Hello, "
.build();
LineBreaker lb = new LineBreaker.Builder()
// Use simple line breaker
.setBreakStrategy(LineBreaker.BREAK_STRATEGY_SIMPLE)
// Do not add hyphenation.
.setHyphenationFrequency(LineBreaker.HYPHENATION_FREQUENCY_NONE)
// Build the LineBreaker
.build();
ParagraphConstraints c = new ParagraphConstraints();
c.setWidth(240); // Set the line wieth as 1024px
// Do the line breaking
Result r = lb.computeLineBreaks(mt, c, 0);
// Compute the total height of the text.
float totalHeight = 0;
for (int i = 0; i < r.getLineCount(); ++i) { // iterate over the lines
totalHeight += r.getLineDescent(i) - r.getLineAscent(i);
}
// Draw text to the canvas
Bitmap bmp = Bitmap.createBitmap(240, totalHeight, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(bmp);
float yOffset = 0f;
int prevOffset = 0;
for (int i = 0; i < r.getLineCount(); ++i) { // iterate over the lines
int nextOffset = r.getLineBreakOffset(i);
c.drawText(text, prevOffset, nextOffset, 0f, yOffset, paint);
prevOffset = nextOffset;
yOffset += r.getLineDescent(i) - r.getLineAscent(i);
}
</code>
Summary
| Nested classes | |
|---|---|
|
Helper class for creating a |
|
| open |
Line breaking constraints for single paragraph. |
| open |
Holds the result of the |
| Constants | |
|---|---|
| static Int |
Value for break strategy indicating balanced line breaking. |
| static Int |
Value for break strategy indicating high quality line breaking. |
| static Int |
Value for break strategy indicating simple line breaking. |
| static Int |
Value for hyphenation frequency indicating the full amount of automatic hyphenation. |
| static Int |
Value for hyphenation frequency indicating no automatic hyphenation. |
| static Int |
Value for hyphenation frequency indicating a light amount of automatic hyphenation. |
| static Int |
Value for justification mode indicating the text is justified by stretching letter spacing. |
| static Int |
Value for justification mode indicating the text is justified by stretching word spacing. |
| static Int |
Value for justification mode indicating no justification. |
| Public methods | |
|---|---|
| open LineBreaker.Result |
computeLineBreaks(measuredPara: MeasuredText, constraints: LineBreaker.ParagraphConstraints, lineNumber: Int)Break paragraph into lines. |
Constants
BREAK_STRATEGY_BALANCED
static val BREAK_STRATEGY_BALANCED: Int
Value for break strategy indicating balanced line breaking. The line breaker does whole-paragraph optimization for making all lines similar length, and also applies automatic hyphenation when required. This break strategy is good for small screen devices such as watch screens.
Value: 2
BREAK_STRATEGY_HIGH_QUALITY
static val BREAK_STRATEGY_HIGH_QUALITY: Int
Value for break strategy indicating high quality line breaking. With this option line breaker does whole-paragraph optimization for more readable text, and also applies automatic hyphenation when required.
Value: 1
BREAK_STRATEGY_SIMPLE
static val BREAK_STRATEGY_SIMPLE: Int
Value for break strategy indicating simple line breaking. The line breaker puts words to the line as much as possible and breaks line if no more words can fit into the same line. Automatic hyphens are only added when a line has a single word and that word is longer than line width. This is the fastest break strategy and ideal for editor.
Value: 0
HYPHENATION_FREQUENCY_FULL
static val HYPHENATION_FREQUENCY_FULL: Int
Value for hyphenation frequency indicating the full amount of automatic hyphenation. This hyphenation frequency is useful for running text and where it's important to put the maximum amount of text in a screen with limited space.
Value: 2
HYPHENATION_FREQUENCY_NONE
static val HYPHENATION_FREQUENCY_NONE: Int
Value for hyphenation frequency indicating no automatic hyphenation. Using this option disables auto hyphenation which results in better text layout performance. A word may be broken without hyphens when a line has a single word and that word is longer than line width. Soft hyphens are ignored and will not be used as suggestions for potential line breaks.
Value: 0
HYPHENATION_FREQUENCY_NORMAL
static val HYPHENATION_FREQUENCY_NORMAL: Int
Value for hyphenation frequency indicating a light amount of automatic hyphenation. This hyphenation frequency is useful for informal cases, such as short sentences or chat messages.
Value: 1
JUSTIFICATION_MODE_INTER_CHARACTER
static val JUSTIFICATION_MODE_INTER_CHARACTER: Int
Value for justification mode indicating the text is justified by stretching letter spacing.
Value: 2
JUSTIFICATION_MODE_INTER_WORD
static val JUSTIFICATION_MODE_INTER_WORD: Int
Value for justification mode indicating the text is justified by stretching word spacing.
Value: 1
JUSTIFICATION_MODE_NONE
static val JUSTIFICATION_MODE_NONE: Int
Value for justification mode indicating no justification.
Value: 0
Public methods
computeLineBreaks
open fun computeLineBreaks(
measuredPara: MeasuredText,
constraints: LineBreaker.ParagraphConstraints,
lineNumber: Int
): LineBreaker.Result
Break paragraph into lines. The result is filled to out param.
| Parameters | |
|---|---|
measuredPara |
MeasuredText: a result of the text measurement This value cannot be null. |
constraints |
LineBreaker.ParagraphConstraints: for a single paragraph This value cannot be null. |
lineNumber |
Int: a line number of this paragraph Value is 0 or greater |
| Return | |
|---|---|
LineBreaker.Result |
This value cannot be null. |