仿微信GIF.gif
1. 自定义view
package com.zss.weixin;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.os.Bundle;
import android.os.Looper;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
public class ChangeColorIconWithText extends View {
private int mColor = 0xFFEB6100;
private Bitmap mIconBitmap;
private String mText = "微信";
private int mTextSize = (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_SP, 12, getResources().getDisplayMetrics());
private Canvas mCanvas;
private Bitmap mBitmap;
private Paint mPaint;
private float mAlpha;
private Rect mIconRect;
private Rect mTextBound;
private Paint mTextPaint;
public ChangeColorIconWithText(Context context) {
this(context, null);
}
public ChangeColorIconWithText(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
/**
* 获取自定义属性的值
*
* @param context
* @param attrs
* @param defStyleAttr
*/
public ChangeColorIconWithText(Context context, AttributeSet attrs,
int defStyleAttr) {
super(context, attrs, defStyleAttr);
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.ChangeColorIconWithText);
int n = a.getIndexCount();
for (int i = 0; i < n; i++) {
int attr = a.getIndex(i);
switch (attr) {
case R.styleable.ChangeColorIconWithText_icon:
BitmapDrawable drawable = (BitmapDrawable) a.getDrawable(attr);
mIconBitmap = drawable.getBitmap();
break;
case R.styleable.ChangeColorIconWithText_color:
mColor = a.getColor(attr, 0xFFEB6100);
break;
case R.styleable.ChangeColorIconWithText_text:
mText = a.getString(attr);
break;
case R.styleable.ChangeColorIconWithText_text_size:
mTextSize = (int) a.getDimension(attr, TypedValue
.applyDimension(TypedValue.COMPLEX_UNIT_SP, 12,
getResources().getDisplayMetrics()));
break;
}
}
a.recycle();
mTextBound = new Rect();
mTextPaint = new Paint();
mTextPaint.setTextSize(mTextSize);
mTextPaint.setColor(0Xff555555);
mTextPaint.getTextBounds(mText, 0, mText.length(), mTextBound);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int iconWidth = Math.min(getMeasuredWidth() - getPaddingLeft()
- getPaddingRight(), getMeasuredHeight() - getPaddingTop()
- getPaddingBottom() - mTextBound.height());
int left = getMeasuredWidth() / 2 - iconWidth / 2;
int top = getMeasuredHeight() / 2 - (mTextBound.height() + iconWidth)
/ 2;
mIconRect = new Rect(left, top, left + iconWidth, top + iconWidth);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mIconBitmap, null, mIconRect, null);
int alpha = (int) Math.ceil(255 * mAlpha);
// 内存去准备mBitmap , setAlpha , 纯色 ，xfermode ， 图标
setupTargetBitmap(alpha);
// 1、绘制原文本 ； 2、绘制变色的文本
drawSourceText(canvas, alpha);
drawTargetText(canvas, alpha);
canvas.drawBitmap(mBitmap, 0, 0, null);
}
/**
* 绘制变色的文本
*
* @param canvas
* @param alpha
*/
private void drawTargetText(Canvas canvas, int alpha) {
mTextPaint.setColor(mColor);
mTextPaint.setAlpha(alpha);
int x = getMeasuredWidth() / 2 - mTextBound.width() / 2;
int y = mIconRect.bottom + mTextBound.height();
canvas.drawText(mText, x, y, mTextPaint);
}
/**
* 绘制原文本
*
* @param canvas
* @param alpha
*/
private void drawSourceText(Canvas canvas, int alpha) {
mTextPaint.setColor(0xff333333);
mTextPaint.setAlpha(255 - alpha);
int x = getMeasuredWidth() / 2 - mTextBound.width() / 2;
int y = mIconRect.bottom + mTextBound.height();
canvas.drawText(mText, x, y, mTextPaint);
}
/**
* 在内存中绘制可变色的Icon
*/
private void setupTargetBitmap(int alpha) {
mBitmap = Bitmap.createBitmap(getMeasuredWidth(), getMeasuredHeight(),
Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPaint = new Paint();
mPaint.setColor(mColor);
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setAlpha(alpha);
mCanvas.drawRect(mIconRect, mPaint);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
mPaint.setAlpha(255);
mCanvas.drawBitmap(mIconBitmap, null, mIconRect, mPaint);
}
private static final String INSTANCE_STATUS = "instance_status";
private static final String STATUS_ALPHA = "status_alpha";
@Override
protected Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable(INSTANCE_STATUS, super.onSaveInstanceState());
bundle.putFloat(STATUS_ALPHA, mAlpha);
return bundle;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
mAlpha = bundle.getFloat(STATUS_ALPHA);
super.onRestoreInstanceState(bundle.getParcelable(INSTANCE_STATUS));
return;
}
super.onRestoreInstanceState(state);
}
public void setIconAlpha(float alpha) {
this.mAlpha = alpha;
invalidateView();
}
/**
* 重绘
*/
private void invalidateView() {
if (Looper.getMainLooper() == Looper.myLooper()) {
invalidate();
} else {
postInvalidate();
}
}
}
2. 使用
3. 逻辑
private List mTabIndicators = new ArrayList();
ChangeColorIconWithText one = (ChangeColorIconWithText) findViewById(R.id.id_indicator_one);
mTabIndicators.add(one);
ChangeColorIconWithText two = (ChangeColorIconWithText) findViewById(R.id.id_indicator_two);
mTabIndicators.add(two);
ChangeColorIconWithText three = (ChangeColorIconWithText) findViewById(R.id.id_indicator_three);
mTabIndicators.add(three);
ChangeColorIconWithText four = (ChangeColorIconWithText) findViewById(R.id.id_indicator_four);
mTabIndicators.add(four);
one.setOnClickListener(this);
two.setOnClickListener(this);
three.setOnClickListener(this);
four.setOnClickListener(this);
one.setIconAlpha(1.0f);
/**
* 点击Tab按钮
*
* @param v
*/
private void clickTab(View v) {
resetOtherTabs();
switch (v.getId()) {
case R.id.id_indicator_one:
mTabIndicators.get(0).setIconAlpha(1.0f);
mViewPager.setCurrentItem(0, false);
break;
case R.id.id_indicator_two:
mTabIndicators.get(1).setIconAlpha(1.0f);
mViewPager.setCurrentItem(1, false);
break;
case R.id.id_indicator_three:
mTabIndicators.get(2).setIconAlpha(1.0f);
mViewPager.setCurrentItem(2, false);
break;
case R.id.id_indicator_four:
mTabIndicators.get(3).setIconAlpha(1.0f);
mViewPager.setCurrentItem(3, false);
break;
}
}
/**
* 重置其他的TabIndicator的颜色
*/
private void resetOtherTabs() {
for (int i = 0; i < mTabIndicators.size(); i++) {
mTabIndicators.get(i).setIconAlpha(0);
}
}
@Override
public void onPageScrolled(int position, float positionOffset,
int positionOffsetPixels) {
// Log.e("TAG", "position = " + position + " ,positionOffset = "
// + positionOffset);
if (positionOffset > 0) {
ChangeColorIconWithText left = mTabIndicators.get(position);
ChangeColorIconWithText right = mTabIndicators.get(position + 1);
left.setIconAlpha(1 - positionOffset);
right.setIconAlpha(positionOffset);
}
}
demo地址:https://github.com/zssAndroid/-view-6.0-