自定义Drawable，增加渐变阴影、部分渐变（圆角、部分圆角、圆形）
一、先上效果图
效果图
二、思路
1、圆角
1）绘制shadow
* 2）绘制遮挡部分shadow
3）绘制圆角图
2、部分圆角
1）绘制shadow
* 2）绘制遮挡部分shadow
3）绘制圆角图
4）绘制遮挡部分圆角
3、圆形
1）绘制shadow
* 2）绘制遮挡部分shadow
3）绘制圆形图
四、实现
1）设置paint
/**
* 阴影paint
*/
mShadowPaint = new Paint();
mShadowPaint.setAntiAlias(true);
mShadowPaint.setShadowLayer(shadowRadius, 0, 0, shadowColor);
/**
* 覆盖部分背景的paint
*/
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
/**
* 背景paint
*/
mBgPaint = new Paint();
mBgPaint.setAntiAlias(true);
/**
* 覆盖部分圆角的paint
*/
mBgPartPaint = new Paint();
mBgPartPaint.setAntiAlias(true);
图像合成效果示意图
设置 覆盖部分背景的paint DST_OUT 显示不重叠的部分
2）根据类型设置RectF
***** 根据类型设置RectF ******
@Override
public void setBounds(int left, int top, int right, int bottom) {
super.setBounds(left, top, right, bottom);
switch (type) {
case All:
left = left + mShadowRadius;
top = top + mShadowRadius;
right = right - mShadowRadius;
bottom = bottom - mShadowRadius;
break;
case TOP:
case BOTTOM:
top = top + mShadowRadius;
bottom = bottom - mShadowRadius;
break;
case LEFT:
case RIGHT:
left = left + mShadowRadius;
right = right - mShadowRadius;
break;
default:
break;
}
mRect = new RectF(left, top, right, bottom);
}
3）根据类型设置覆盖阴影/圆角 的 RectF
/**
* 设置覆盖阴影/圆角 的 RectF
*/
RectF rect = new RectF();
RectF rect1 = new RectF();
switch (type) {
case All:
rect.left = 0;
rect.right = 0;
rect.top = 0;
rect.bottom = 0;
break;
case TOP:
rect.left = mRect.left;
rect.right = mRect.right;
rect.top = mRect.height() / 2;
rect.bottom = mRect.bottom + mShadowRadius;
rect1.left = mRect.left;
rect1.right = mRect.right;
rect1.top = mRect.height() / 2;
rect1.bottom = mRect.bottom;
break;
case BOTTOM:
rect.left = mRect.left;
rect.right = mRect.right;
rect.top = mRect.top - mShadowRadius;
rect.bottom = mRect.height() / 2;
rect1.left = mRect.left;
rect1.right = mRect.right;
rect1.top = mRect.top;
rect1.bottom = mRect.height() / 2;
break;
case LEFT:
rect.left = mRect.width() / 2;
rect.right = mRect.right + mShadowRadius;
rect.top = mRect.top;
rect.bottom = mRect.bottom;
rect1.left = mRect.width() / 2;
rect1.right = mRect.right ;
rect1.top = mRect.top;
rect1.bottom = mRect.bottom;
break;
case RIGHT:
rect.left = mRect.left-mShadowRadius;
rect.right = mRect.width() / 2;
rect.top = mRect.top;
rect.bottom = mRect.bottom;
rect1.left = mRect.left;
rect1.right = mRect.width() / 2;
rect1.top = mRect.top;
rect1.bottom = mRect.bottom;
break;
default:
break;
}
4）根据 类型绘制 背景
if (mShape == SHAPE_ROUND) {
/**
* 绘制全圆角阴影
*/
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mShadowPaint);//绘制阴影
canvas.drawRect(rect, mPaint);//绘制不需显示阴影部分的遮盖
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mBgPaint);//绘制中心的图
} else if (mShape == SHAPE_ROUND_PART) {
/**
* 绘制部分圆角阴影
*/
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mShadowPaint);//绘制阴影
canvas.drawRect(rect, mPaint);//绘制不需显示阴影部分的遮盖
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mBgPaint);//绘制中心的图
canvas.drawRect(rect1, mBgPartPaint);//绘制不需显示圆角的部分
} else {
/**
* 绘制圆形阴影
*/
canvas.drawCircle(mRect.centerX(), mRect.centerY(), Math.min(mRect.width(), mRect.height()) / 2, mShadowPaint);//绘制带阴影的圆形
canvas.drawRect(rect, mPaint);//绘制不需显示阴影部分的遮盖
canvas.drawCircle(mRect.centerX(), mRect.centerY(), Math.min(mRect.width(), mRect.height()) / 2, mBgPaint);//绘制中心圆
}
4）使用（就是这么简单）
ShadowDrawableUtil.setShadowDrawable(round_tv, ShadowDrawableUtil.TypeEnum.LEFT);
ShadowDrawableUtil.setShadowDrawableTop(round_part_tv,"#A6000000");
ShadowDrawableUtil.setShadowDrawableCircle(circle_tv);
6）RoundImageView完整代码
/**
* view 添加阴影
*/
public class ShadowDrawableUtil extends Drawable {
private Paint mShadowPaint;
private Paint mBgPaint;
private Paint mPaint;
private Paint mBgPartPaint;
private int mShadowRadius;
private int mShape;
private int mShapeRadius;
private int mBgColor[];
private RectF mRect;
private TypeEnum type;
private static int SHAPE_ROUND = 1;
private static int SHAPE_CIRCLE = 2;
private static int SHAPE_ROUND_PART = 3;
public enum TypeEnum {
All,
LEFT,
TOP,
RIGHT,
BOTTOM
}
private ShadowDrawableUtil(int shape, TypeEnum type, int[] bgColor, int shapeRadius, int shadowColor, int shadowRadius) {
this.mShape = shape;
this.type = type;
this.mBgColor = bgColor;
this.mShapeRadius = shapeRadius;
this.mShadowRadius = shadowRadius;
/**
* 阴影paint
*/
mShadowPaint = new Paint();
mShadowPaint.setAntiAlias(true);
mShadowPaint.setShadowLayer(shadowRadius, 0, 0, shadowColor);
/**
* 覆盖部分背景的paint
*/
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
/**
* 背景paint
*/
mBgPaint = new Paint();
mBgPaint.setAntiAlias(true);
/**
* 覆盖部分圆角的paint
*/
mBgPartPaint = new Paint();
mBgPartPaint.setAntiAlias(true);
}
@Override
public void setBounds(int left, int top, int right, int bottom) {
super.setBounds(left, top, right, bottom);
switch (type) {
case All:
left = left + mShadowRadius;
top = top + mShadowRadius;
right = right - mShadowRadius;
bottom = bottom - mShadowRadius;
break;
case TOP:
case BOTTOM:
top = top + mShadowRadius;
bottom = bottom - mShadowRadius;
break;
case LEFT:
case RIGHT:
left = left + mShadowRadius;
right = right - mShadowRadius;
break;
default:
break;
}
mRect = new RectF(left, top, right, bottom);
}
@Override
public void draw(@NonNull Canvas canvas) {
if (mBgColor != null) {
if (mBgColor.length == 1) {
mBgPaint.setColor(mBgColor[0]);
mShadowPaint.setColor(mBgColor[0]);
mBgPartPaint.setColor(mBgColor[0]);
} else {
mBgPaint.setShader(new LinearGradient(mRect.left, mRect.height() / 2, mRect.right,
mRect.height() / 2, mBgColor, null, Shader.TileMode.CLAMP));
}
}
/**
* 设置覆盖阴影/圆角 的 RectF
*/
RectF rect = new RectF();
RectF rect1 = new RectF();
switch (type) {
case All:
rect.left = 0;
rect.right = 0;
rect.top = 0;
rect.bottom = 0;
break;
case TOP:
rect.left = mRect.left;
rect.right = mRect.right;
rect.top = mRect.height() / 2;
rect.bottom = mRect.bottom + mShadowRadius;
rect1.left = mRect.left;
rect1.right = mRect.right;
rect1.top = mRect.height() / 2;
rect1.bottom = mRect.bottom;
break;
case BOTTOM:
rect.left = mRect.left;
rect.right = mRect.right;
rect.top = mRect.top - mShadowRadius;
rect.bottom = mRect.height() / 2;
rect1.left = mRect.left;
rect1.right = mRect.right;
rect1.top = mRect.top;
rect1.bottom = mRect.height() / 2;
break;
case LEFT:
rect.left = mRect.width() / 2;
rect.right = mRect.right + mShadowRadius;
rect.top = mRect.top;
rect.bottom = mRect.bottom;
rect1.left = mRect.width() / 2;
rect1.right = mRect.right ;
rect1.top = mRect.top;
rect1.bottom = mRect.bottom;
break;
case RIGHT:
rect.left = mRect.left-mShadowRadius;
rect.right = mRect.width() / 2;
rect.top = mRect.top;
rect.bottom = mRect.bottom;
rect1.left = mRect.left;
rect1.right = mRect.width() / 2;
rect1.top = mRect.top;
rect1.bottom = mRect.bottom;
break;
default:
break;
}
if (mShape == SHAPE_ROUND) {
/**
* 绘制全圆角阴影
*/
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mShadowPaint);
canvas.drawRect(rect, mPaint);
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mBgPaint);
} else if (mShape == SHAPE_ROUND_PART) {
/**
* 绘制部分圆角阴影
*/
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mShadowPaint);
canvas.drawRect(rect, mPaint);
canvas.drawRoundRect(mRect, mShapeRadius, mShapeRadius, mBgPaint);
canvas.drawRect(rect1, mBgPartPaint);
} else {
/**
* 绘制圆形阴影
*/
canvas.drawCircle(mRect.centerX(), mRect.centerY(), Math.min(mRect.width(), mRect.height()) / 2, mShadowPaint);
canvas.drawRect(rect, mPaint);
canvas.drawCircle(mRect.centerX(), mRect.centerY(), Math.min(mRect.width(), mRect.height()) / 2, mBgPaint);
}
}
@Override
public void setAlpha(int alpha) {
mShadowPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(@Nullable ColorFilter colorFilter) {
mShadowPaint.setColorFilter(colorFilter);
}
@Override
public int getOpacity() {
return PixelFormat.TRANSLUCENT;
}
public static void setShadowDrawable(View view) {
ShadowDrawableUtil drawable = new Builder()
.setType(TypeEnum.BOTTOM)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
public static void setShadowDrawable(View view, String bgColor) {
ShadowDrawableUtil drawable = new Builder()
.setType(TypeEnum.BOTTOM)
.setBgColor(bgColor)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
public static void setShadowDrawable(View view, TypeEnum type) {
ShadowDrawableUtil drawable = new Builder()
.setType(type)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
public static void setShadowDrawableCircle(View view) {
ShadowDrawableUtil drawable = new Builder()
.setShape(SHAPE_CIRCLE)
.setType(TypeEnum.All)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
public static void setShadowDrawableTop(View view, String shapeColor) {
ShadowDrawableUtil drawable = new Builder()
.setShape(SHAPE_ROUND_PART)
.setType(TypeEnum.TOP)
.setShadowColor(shapeColor)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
public static void setShadowDrawable(View view, String shapeColor, int shapeRadius, String shadowColor, int shadowRadius) {
ShadowDrawableUtil drawable = new Builder()
.setBgColor(shapeColor)
.setShapeRadius(shapeRadius)
.setShadowColor(shadowColor)
.setShadowRadius(shadowRadius)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
public static void setShadowDrawable(View view, int shape, TypeEnum type, String shapeColor, int shapeRadius, String shadowColor, int shadowRadius) {
ShadowDrawableUtil drawable = new Builder()
.setBgColor(shapeColor)
.setShapeRadius(shapeRadius)
.setShadowColor(shadowColor)
.setShadowRadius(shadowRadius)
.setShape(shape)
.setType(type)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
public static void setShadowDrawable(View view, int shape, TypeEnum type, String[] shapeColor, int shapeRadius, String shadowColor, int shadowRadius) {
ShadowDrawableUtil drawable = new Builder()
.setBgColor(shapeColor)
.setShapeRadius(shapeRadius)
.setShadowColor(shadowColor)
.setShadowRadius(shadowRadius)
.setShape(shape)
.setType(type)
.builder();
view.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
ViewCompat.setBackground(view, drawable);
}
private static class Builder {
private int mShape;
private int mShapeRadius;
private int mShadowColor;
private int mShadowRadius;
private int[] mBgColor;
private TypeEnum type;
private Builder() {
mShape = SHAPE_ROUND;
type = TypeEnum.All;
mShapeRadius = 17;
mShadowColor = Color.parseColor("#FF0000");
mShadowRadius = 4;
mBgColor = new int[1];
mBgColor[0] = Color.GREEN;
}
private Builder setShape(int mShape) {
this.mShape = mShape;
return this;
}
private Builder setShapeRadius(int ShapeRadius) {
this.mShapeRadius = ShapeRadius;
return this;
}
private Builder setShadowColor(String shadowColor) {
this.mShadowColor = Color.parseColor(shadowColor);
return this;
}
private Builder setShadowRadius(int shadowRadius) {
this.mShadowRadius = shadowRadius;
return this;
}
private Builder setBgColor(String bgColor) {
this.mBgColor[0] = Color.parseColor(bgColor);
return this;
}
private Builder setType(TypeEnum type) {
this.type = type;
return this;
}
private Builder setBgColor(String[] bgColors) {
if (bgColors != null && bgColors.length > 0) {
int[] b = new int[bgColors.length];
for (int i = 0; i < bgColors.length; i++) {
b[i] = Color.parseColor(bgColors[i]);
}
this.mBgColor = b;
}
return this;
}
private ShadowDrawableUtil builder() {
return new ShadowDrawableUtil(mShape, type, mBgColor, dp2px(mShapeRadius), mShadowColor, dp2px(mShadowRadius));
}
}
private static int dp2px(float dpVal) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dpVal, ShadowApplication.getApplication().getResources().getDisplayMetrics());
}
}
如有意见和建议，及时沟通。
