Text Align
/*
* Copyright (C) 2007 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 app.test;
import android.app.Activity;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Picture;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
public class Test extends GraphicsActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new SampleView(this));
}
private static class SampleView extends View {
private Paint mPaint;
private float mX;
private float[] mPos;
private Path mPath;
private Paint mPathPaint;
private static final int DY = 30;
private static final String TEXT_L = "Left";
private static final String TEXT_C = "Center";
private static final String TEXT_R = "Right";
private static final String POSTEXT = "Positioned";
private static final String TEXTONPATH = "Along a path";
private static void makePath(Path p) {
p.moveTo(10, 0);
p.cubicTo(100, -50, 200, 50, 300, 0);
}
private float[] buildTextPositions(String text, float y, Paint paint) {
float[] widths = new float[text.length()];
// initially get the widths for each char
int n = paint.getTextWidths(text, widths);
// now popuplate the array, interleaving spaces for the Y values
float[] pos = new float[n * 2];
float accumulatedX = 0;
for (int i = 0; i < n; i++) {
pos[i * 2 + 0] = accumulatedX;
pos[i * 2 + 1] = y;
accumulatedX += widths[i];
}
return pos;
}
public SampleView(Context context) {
super(context);
setFocusable(true);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setTextSize(30);
mPaint.setTypeface(Typeface.SERIF);
mPos = buildTextPositions(POSTEXT, 0, mPaint);
mPath = new Path();
makePath(mPath);
mPathPaint = new Paint();
mPathPaint.setAntiAlias(true);
mPathPaint.setColor(0x800000FF);
mPathPaint.setStyle(Paint.Style.STROKE);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.WHITE);
Paint p = mPaint;
float x = mX;
float y = 0;
float[] pos = mPos;
// draw the normal strings
p.setColor(0x80FF0000);
canvas.drawLine(x, y, x, y + DY * 3, p);
p.setColor(Color.BLACK);
canvas.translate(0, DY);
p.setTextAlign(Paint.Align.LEFT);
canvas.drawText(TEXT_L, x, y, p);
canvas.translate(0, DY);
p.setTextAlign(Paint.Align.CENTER);
canvas.drawText(TEXT_C, x, y, p);
canvas.translate(0, DY);
p.setTextAlign(Paint.Align.RIGHT);
canvas.drawText(TEXT_R, x, y, p);
canvas.translate(100, DY * 2);
// now draw the positioned strings
p.setColor(0xBB00FF00);
for (int i = 0; i < pos.length / 2; i++) {
canvas.drawLine(pos[i * 2 + 0], pos[i * 2 + 1] - DY,
pos[i * 2 + 0], pos[i * 2 + 1] + DY * 2, p);
}
p.setColor(Color.BLACK);
p.setTextAlign(Paint.Align.LEFT);
canvas.drawPosText(POSTEXT, pos, p);
canvas.translate(0, DY);
p.setTextAlign(Paint.Align.CENTER);
canvas.drawPosText(POSTEXT, pos, p);
canvas.translate(0, DY);
p.setTextAlign(Paint.Align.RIGHT);
canvas.drawPosText(POSTEXT, pos, p);
// now draw the text on path
canvas.translate(-100, DY * 2);
canvas.drawPath(mPath, mPathPaint);
p.setTextAlign(Paint.Align.LEFT);
canvas.drawTextOnPath(TEXTONPATH, mPath, 0, 0, p);
canvas.translate(0, DY * 1.5f);
canvas.drawPath(mPath, mPathPaint);
p.setTextAlign(Paint.Align.CENTER);
canvas.drawTextOnPath(TEXTONPATH, mPath, 0, 0, p);
canvas.translate(0, DY * 1.5f);
canvas.drawPath(mPath, mPathPaint);
p.setTextAlign(Paint.Align.RIGHT);
canvas.drawTextOnPath(TEXTONPATH, mPath, 0, 0, p);
}
@Override
protected void onSizeChanged(int w, int h, int ow, int oh) {
super.onSizeChanged(w, h, ow, oh);
mX = w * 0.5f; // remember the center of the screen
}
}
}
class GraphicsActivity extends Activity {
// set to true to test Picture
private static final boolean TEST_PICTURE = false;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public void setContentView(View view) {
if (TEST_PICTURE) {
ViewGroup vg = new PictureLayout(this);
vg.addView(view);
view = vg;
}
super.setContentView(view);
}
}
class PictureLayout extends ViewGroup {
private final Picture mPicture = new Picture();
public PictureLayout(Context context) {
super(context);
}
public PictureLayout(Context context, AttributeSet attrs) {
super(context, attrs);
}
@Override
public void addView(View child) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child);
}
@Override
public void addView(View child, int index) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, index);
}
@Override
public void addView(View child, LayoutParams params) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, params);
}
@Override
public void addView(View child, int index, LayoutParams params) {
if (getChildCount() > 1) {
throw new IllegalStateException(
"PictureLayout can host only one direct child");
}
super.addView(child, index, params);
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int count = getChildCount();
int maxHeight = 0;
int maxWidth = 0;
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
measureChild(child, widthMeasureSpec, heightMeasureSpec);
}
}
maxWidth += getPaddingLeft() + getPaddingRight();
maxHeight += getPaddingTop() + getPaddingBottom();
Drawable drawable = getBackground();
if (drawable != null) {
maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
}
setMeasuredDimension(resolveSize(maxWidth, widthMeasureSpec),
resolveSize(maxHeight, heightMeasureSpec));
}
private void drawPict(Canvas canvas, int x, int y, int w, int h, float sx,
float sy) {
canvas.save();
canvas.translate(x, y);
canvas.clipRect(0, 0, w, h);
canvas.scale(0.5f, 0.5f);
canvas.scale(sx, sy, w, h);
canvas.drawPicture(mPicture);
canvas.restore();
}
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(mPicture.beginRecording(getWidth(), getHeight()));
mPicture.endRecording();
int x = getWidth() / 2;
int y = getHeight() / 2;
if (false) {
canvas.drawPicture(mPicture);
} else {
drawPict(canvas, 0, 0, x, y, 1, 1);
drawPict(canvas, x, 0, x, y, -1, 1);
drawPict(canvas, 0, y, x, y, 1, -1);
drawPict(canvas, x, y, x, y, -1, -1);
}
}
@Override
public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
location[0] = getLeft();
location[1] = getTop();
dirty.set(0, 0, getWidth(), getHeight());
return getParent();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int count = super.getChildCount();
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
final int childLeft = getPaddingLeft();
final int childTop = getPaddingTop();
child.layout(childLeft, childTop,
childLeft + child.getMeasuredWidth(),
childTop + child.getMeasuredHeight());
}
}
}
}
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