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@ponnamkarthik
Created October 30, 2017 14:00
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Justify TextView android
package com.ghm.rtoexam.utils;
/**
* Created by ponna on 16-08-2017.
*/
import android.content.Context;
import android.graphics.Canvas;
import android.support.v7.widget.AppCompatTextView;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
public class JustifyTextView extends AppCompatTextView {
private int mLineY;
private int mViewWidth;
public JustifyTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
}
@Override
protected void onDraw(Canvas canvas) {
TextPaint paint = getPaint();
paint.setColor(getCurrentTextColor());
paint.drawableState = getDrawableState();
mViewWidth = getMeasuredWidth();
String text = getText().toString();
mLineY = 0;
mLineY += getTextSize();
Layout layout = getLayout();
for (int i = 0; i < layout.getLineCount(); i++) {
int lineStart = layout.getLineStart(i);
int lineEnd = layout.getLineEnd(i);
String line = text.substring(lineStart, lineEnd);
float width = StaticLayout.getDesiredWidth(text, lineStart, lineEnd, getPaint());
if (needScale(line,i)) {
drawScaledText(canvas, lineStart, line, width);
} else {
canvas.drawText(line, 0, mLineY, paint);
}
mLineY += getLineHeight();
}
}
private void drawScaledText(Canvas canvas, int lineStart, String line, float lineWidth) {
float x = 0;
if (isFirstLineOfParagraph(lineStart, line)) {
String blanks = " ";
canvas.drawText(blanks, x, mLineY, getPaint());
float bw = StaticLayout.getDesiredWidth(blanks, getPaint());
x += bw;
line = line.substring(3);
}
float d = (mViewWidth - lineWidth) / line.length() - 1;
for (int i = 0; i < line.length(); i++) {
String c = String.valueOf(line.charAt(i));
float cw = StaticLayout.getDesiredWidth(c, getPaint());
canvas.drawText(c, x, mLineY, getPaint());
x += cw + d;
}
}
private boolean isFirstLineOfParagraph(int lineStart, String line) {
return line.length() > 3 && line.charAt(0) == ' ' && line.charAt(1) == ' ';
}
private boolean needScale(String line,int lineNumber) {
Layout layout = getLayout();
if (line.length() == 0 || layout.getLineCount() == 1 || lineNumber == (layout.getLineCount() - 1)) {
return false;
} else {
return line.charAt(line.length() - 1) != '\n';
}
}
}
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