android-circlebutton

工程源码 https://github.com/hgl888/android-circlebutton

使用实例如下：

<FrameLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:layout_width="match_parent"    android:layout_height="match_parent" >    <at.markushi.ui.CircleButton        android:layout_width="64dip"        android:layout_height="64dip"        android:src="@drawable/ic_action_tick"        app:cb_color="#99CC00"        app:cb_pressedRingWidth="8dip" /></FrameLayout>

主要功能是在CircleButton，圆形按钮在点击是会出现光晕效果，主要在

private void showPressedRing() {
pressedAnimator.setFloatValues(animationProgress, pressedRingWidth);
pressedAnimator.start();
}

函数中，在init函数中初始化pressedAnimator，在该函数中，启动动画，

该类完整代码如下：

package at.markushi.ui;


import android.animation.ObjectAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.ImageView;


import at.markushi.circlebutton.R;


public class CircleButton extends ImageView {


private static final int PRESSED_COLOR_LIGHTUP = 255 / 25;
private static final int PRESSED_RING_ALPHA = 75;
private static final int DEFAULT_PRESSED_RING_WIDTH_DIP = 4;
private static final int ANIMATION_TIME_ID = android.R.integer.config_shortAnimTime;


private int centerY;
private int centerX;
private int outerRadius;
private int pressedRingRadius;


private Paint circlePaint;
private Paint focusPaint;


private float animationProgress;


private int pressedRingWidth;
private int defaultColor = Color.BLACK;
private int pressedColor;
private ObjectAnimator pressedAnimator;


public CircleButton(Context context) {
super(context);
init(context, null);
}


public CircleButton(Context context, AttributeSet attrs) {
super(context, attrs);
init(context, attrs);
}


public CircleButton(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context, attrs);
}


@Override
public void setPressed(boolean pressed) {
super.setPressed(pressed);


if (circlePaint != null) {
circlePaint.setColor(pressed ? pressedColor : defaultColor);
}


if (pressed) {
showPressedRing();
} else {
hidePressedRing();
}
}


@Override
protected void onDraw(Canvas canvas) {
canvas.drawCircle(centerX, centerY, pressedRingRadius + animationProgress, focusPaint);
canvas.drawCircle(centerX, centerY, outerRadius - pressedRingWidth, circlePaint);
super.onDraw(canvas);
}


@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
centerX = w / 2;
centerY = h / 2;
outerRadius = Math.min(w, h) / 2;
pressedRingRadius = outerRadius - pressedRingWidth - pressedRingWidth / 2;
}


public float getAnimationProgress() {
return animationProgress;
}


public void setAnimationProgress(float animationProgress) {
this.animationProgress = animationProgress;
this.invalidate();
}


public void setColor(int color) {
this.defaultColor = color;
this.pressedColor = getHighlightColor(color, PRESSED_COLOR_LIGHTUP);


circlePaint.setColor(defaultColor);
focusPaint.setColor(defaultColor);
focusPaint.setAlpha(PRESSED_RING_ALPHA);


this.invalidate();
}


private void hidePressedRing() {
pressedAnimator.setFloatValues(pressedRingWidth, 0f);
pressedAnimator.start();
}


private void showPressedRing() {
pressedAnimator.setFloatValues(animationProgress, pressedRingWidth);
pressedAnimator.start();
}


private void init(Context context, AttributeSet attrs) {
this.setFocusable(true);
this.setScaleType(ScaleType.CENTER_INSIDE);
setClickable(true);


circlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
circlePaint.setStyle(Paint.Style.FILL);


focusPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
focusPaint.setStyle(Paint.Style.STROKE);


pressedRingWidth = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, DEFAULT_PRESSED_RING_WIDTH_DIP, getResources()
.getDisplayMetrics());


int color = Color.BLACK;
if (attrs != null) {
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CircleButton);
color = a.getColor(R.styleable.CircleButton_cb_color, color);
pressedRingWidth = (int) a.getDimension(R.styleable.CircleButton_cb_pressedRingWidth, pressedRingWidth);
a.recycle();
}


setColor(color);


focusPaint.setStrokeWidth(pressedRingWidth);
final int pressedAnimationTime = getResources().getInteger(ANIMATION_TIME_ID);
pressedAnimator = ObjectAnimator.ofFloat(this, "animationProgress", 0f, 0f);
pressedAnimator.setDuration(pressedAnimationTime);
}


private int getHighlightColor(int color, int amount) {
return Color.argb(Math.min(255, Color.alpha(color)), Math.min(255, Color.red(color) + amount),
Math.min(255, Color.green(color) + amount), Math.min(255, Color.blue(color) + amount));
}
}