更新为仅在心形内设置透明度。
如果您只需要基于创建的形状戳出图像,则可以使用mafs-image-shape等库,但您需要提供一种在切割图像之前操作形状位置的方法。
我假设您依赖于Android-Image-Cropper
的结构,因此以下更改适用于该库。所示代码基于Android-Image-Cropper中的选定代码,该代码根据Apache License 2.0获得许可。
以下是应用程序进行以下更改后的样子。接下来的讨论解释了如何更改基础代码以适应心形。
除了矩形和椭圆形外,需要将心形定义为一种选项。要将心形作为一个选项,可以更改CropImageView
中的CropShape
枚举,添加HEART
作为裁剪形状,并在attrs
中添加heart
作为cropShape
选项:
CropImageView.java
public enum CropShape {
RECTANGLE,
OVAL,
HEART
}
attrs.xml
<attr name="cropShape">
<enum name="rectangle" value="0"/>
<enum name="oval" value="1"/>
<enum name="heart" value="2"/>
</attr>
我使用了两个图像来制作心形。第一张图像是框架图像,用于将框架定位在底层图像上。裁剪图像与框架图像相同,但是在裁剪操作期间应该保留的位置是实心的(alpha == 1)。透明区域应将alpha设置为零。这是我使用的图像,但您需要使用自己的图像。
CropOverlayView
是一个自定义视图,用于展示裁剪窗口和阴影背景。修改此类的drawBackground
和drawBorders
方法如下,以适应心形。
CropOverlayView.java
private void drawBackground(Canvas canvas) {
RectF rect = mCropWindowHandler.getRect();
float left = Math.max(BitmapUtils.getRectLeft(mBoundsPoints), 0);
float top = Math.max(BitmapUtils.getRectTop(mBoundsPoints), 0);
float right = Math.min(BitmapUtils.getRectRight(mBoundsPoints), getWidth());
float bottom = Math.min(BitmapUtils.getRectBottom(mBoundsPoints), getHeight());
if (mCropShape == CropImageView.CropShape.RECTANGLE) {
if (!isNonStraightAngleRotated() || Build.VERSION.SDK_INT <= 17) {
canvas.drawRect(left, top, right, rect.top, mBackgroundPaint);
canvas.drawRect(left, rect.bottom, right, bottom, mBackgroundPaint);
canvas.drawRect(left, rect.top, rect.left, rect.bottom, mBackgroundPaint);
canvas.drawRect(rect.right, rect.top, right, rect.bottom, mBackgroundPaint);
} else {
mPath.reset();
mPath.moveTo(mBoundsPoints[0], mBoundsPoints[1]);
mPath.lineTo(mBoundsPoints[2], mBoundsPoints[3]);
mPath.lineTo(mBoundsPoints[4], mBoundsPoints[5]);
mPath.lineTo(mBoundsPoints[6], mBoundsPoints[7]);
mPath.close();
canvas.save();
canvas.clipPath(mPath, Region.Op.INTERSECT);
canvas.clipRect(rect, Region.Op.XOR);
canvas.drawRect(left, top, right, bottom, mBackgroundPaint);
canvas.restore();
}
} else if (mCropShape == CropImageView.CropShape.HEART) {
Bitmap screen = Bitmap.createBitmap(canvas.getWidth(), canvas.getHeight(),
Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(screen);
c.drawRect(0, 0, right, bottom, mBackgroundPaint);
Bitmap heart = BitmapFactory.decodeResource(getResources(), R.drawable.heart_image_solid);
heart = Bitmap.createScaledBitmap(heart, (int) rect.width(), (int) rect.height(), true);
Paint paint = new Paint();
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_OUT));
c.drawBitmap(heart, rect.left, rect.top, paint);
heart = BitmapFactory.decodeResource(getResources(), R.drawable.heart_image_frame);
heart = Bitmap.createScaledBitmap(heart, (int) rect.width(), (int) rect.height(), true);
c.drawBitmap(heart, rect.left, rect.top, null);
canvas.drawBitmap(screen, 0, 0, null);
} else {
mPath.reset();
if (Build.VERSION.SDK_INT <= 17 && mCropShape == CropImageView.CropShape.OVAL) {
mDrawRect.set(rect.left + 2, rect.top + 2, rect.right - 2, rect.bottom - 2);
} else {
mDrawRect.set(rect.left, rect.top, rect.right, rect.bottom);
}
mPath.addOval(mDrawRect, Path.Direction.CW);
canvas.save();
canvas.clipPath(mPath, Region.Op.XOR);
canvas.drawRect(left, top, right, bottom, mBackgroundPaint);
canvas.restore();
}
}
private void drawBorders(Canvas canvas) {
if (mBorderPaint != null) {
float w = mBorderPaint.getStrokeWidth();
RectF rect = mCropWindowHandler.getRect();
rect.inset(w / 2, w / 2);
if (mCropShape == CropImageView.CropShape.RECTANGLE) {
canvas.drawRect(rect, mBorderPaint);
} else if (mCropShape == CropImageView.CropShape.OVAL) {
canvas.drawOval(rect, mBorderPaint);
}
}
}
请将以下方法添加到CropImage.java
中。此方法将裁剪出心形图像并加框。
CropImage
public static Bitmap toHeartBitmap(@NonNull Bitmap bitmap, @NonNull Context context) {
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
int color = 0xff424242;
Paint paint = new Paint();
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
RectF rect = new RectF(0, 0, width, height);
Bitmap heart = BitmapFactory.decodeResource(context.getResources(), R.drawable.heart_image_solid);
heart = Bitmap.createScaledBitmap(heart, width, height, true);
canvas.drawBitmap(heart, 0, 0, null);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, 0, 0, paint);
heart = BitmapFactory.decodeResource(context.getResources(), R.drawable.heart_image_frame);
heart = Bitmap.createScaledBitmap(heart, width, height, true);
canvas.drawBitmap(heart, 0, 0, null);
bitmap.recycle();
return output;
}
这是演示应用程序的主活动,展示如何使用心形调用裁剪库:
MainActivity.java
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(R.id.retry).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
cropImage();
}
});
cropImage();
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
CropImage.ActivityResult result = CropImage.getActivityResult(data);
if (result == null) {
return;
}
Uri picUri = result.getUri();
if (picUri == null) {
return;
}
Bitmap bitmap;
bitmap = MediaStore.Images.Media.getBitmap(this.getContentResolver(), picUri);
}
if (bitmap == null) {
return;
}
ImageView imageView = findViewById(R.id.imageView);
imageView.setImageBitmap(CropImage.toHeartBitmap(bitmap, this));
}
private void cropImage() {
CropImage.activity().setGuidelines(CropImageView.Guidelines.ON)
.setCropShape(CropImageView.CropShape.HEART)
.start(MainActivity.this);
}
}