I have LinearLayout containing some views. Is it possible to do so that everything inside LinearLayout are drawn in grayscale color mode?
you need to extends LinearLayout and override dispatchDraw method.
then create a Bitmap with the size of LinearLayout and a canvas. and call super.dispatchDraw with new canvas as parameter. after that you draw the bitmap on the original Canvas with a paint setting a ColorFilter.
here's the example:
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mPaint;
public {Constructor}{
mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.setSaturation(0);
ColorMatrixColorFilter colorFilter = new ColorMatrixColorFilter(colorMatrix);
mPaint.setColorFilter(colorFilter);
}
#Override
public void onSizeChanged(int w, int h, in oldw, int oldh){
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Camvas(mBitmap);
}
#Override
public void dispatchDraw(Canvas canvas){
super.dispatchDraw(mCanvas);
canvas.drawBitmap(mBitmap, 0, 0, mPaint);
}
Related
I draw a bitmap image into a canvas with this code:the bitmap get from user galley
public class CanvasView extends View {
Bitmap canvasBitmap;
Canvas drawCanvas;
public CanvasView(Context context,AttributeSet attrs) {
super(context,attrs);
}
public void setCanvasPath(String bitmap_path) {
BitmapFactory.Options decode_options = new BitmapFactory.Options();
decode_options.inMutable = true;
canvasBitmap = BitmapFactory.decodeFile(bitmap_path,decode_options);
drawCanvas = new Canvas(canvasBitmap);
invalidate();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if (canvasBitmap != null) {
Matrix matrix=new Matrix();
Matrix m = drawCanvas.getMatrix();
RectF drawableRect = new RectF(0, 0, canvasBitmap.getWidth(), canvasBitmap.getHeight());
RectF viewRect = new RectF(0, 0, drawCanvas.getWidth(),drawCanvas.getHeight());
m.setRectToRect(drawableRect, viewRect, Matrix.ScaleToFit.CENTER);
canvas.drawBitmap(canvasBitmap,m , null);
}
}
}
but when i draw the bitmap it get out of the canvas view,i don't want to stretch the image,i want to my canvas act like image view in android.
I have a custom view and I want to get pixel by a given position on ACTION_UP event.
public class MyView extends View
{
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mPaint;
public MyView(Context context)
{
super(context);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh)
{
super.onSizeChanged(w, h, oldw, oldh);
setDrawingCacheEnabled(true);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPaint = new Paint();
mPaint.setColor(Color.RED);
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setStrokeWidth(20f);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
}
#Override
protected void onDraw(Canvas canvas)
{
canvas.drawBitmap(mBitmap, 0, 0, mPaint);
}
#Override
public boolean onTouchEvent(MotionEvent event)
{
switch (event.getAction())
{
case MotionEvent.ACTION_UP:
{
float x = event.getX();
float y = event.getY();
int pixel = mBitmap.getPixel((int) x, (int) y);
Log.i("APP", "Pixel is: " + pixel);
return true;
}
}
return super.onTouchEvent(event);
}
}
I'm getting only 0 when I'm calling mBitmap.getPixel(x, y);
I've marked the ontouch events on the image with black circle
You create a bitmap, and a canvas for that bitmap. But you never draw to it. Since you never draw to it, it will be whatever the default value of a new bitmap is, which is most likely to be either random or 0.
Unless you didn't post the drawing code, in which case we'll need that too.
I am trying to have a custom EditText with a custom background which is not possible to draw using drawable XMLs
Here is what I have right now
public class EMEditText extends EditText {
private Bitmap framedBitmap;
public EMEditText(Context context, AttributeSet attrs) {
super(context, attrs);
// TODO Auto-generated constructor stub
}
#Override
protected void onDraw(Canvas canvas) {
if(framedBitmap == null) {
createDrawable(getWidth(), getHeight());
}
Paint paint = new Paint();
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
// canvas.drawBitmap(framedBitmap, 0, 0, paint);
}
private void createDrawable(int width, int height) {
// create a new bitmap of given size
Bitmap start = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(start);
RectF outerRect = new RectF(0, 0, width, height);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(Color.WHITE);
// paint.setStrokeWidth(1);
// paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT));
canvas.drawRoundRect(outerRect, height / 2, height / 2, paint);
framedBitmap = start;
}
}
What is probably wrong in your code is that you are creating your own Canvas object in createDrawable() method though onDraw() method gives you the right Canvas which you should use for your drawings.
So what you probably want is to change createDrawable(int width, int height) method to createDrawable(int width, int height, Canvas c). Your code should look like this then:
#Override
protected void onDraw(Canvas canvas) {
if(framedBitmap == null) {
createDrawable(getWidth(), getHeight(), canvas);
}
Paint paint = new Paint();
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
// canvas.drawBitmap(framedBitmap, 0, 0, paint);
}
private void createDrawable(int width, int height, Canvas c) {
// create a new bitmap of given size
Bitmap start = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
c.setBitmap(start);
RectF outerRect = new RectF(0, 0, width, height);
Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
paint.setColor(Color.WHITE);
// paint.setStrokeWidth(1);
// paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_OUT));
c.drawRoundRect(outerRect, height / 2, height / 2, paint);
framedBitmap = start;
}
As you can see, I changed also the body of your createDrawable() method so that it uses Canvas from onDraw() and sets it's Bitmap to the one created by you.
I am attempting to draw a bitmap along a rectangle, but I am not sure how to go about it. Is there a way to tile a bitmap along a Rect object using a paint property or something? I have looked, but I can't find anything that makes it do what I need it too, most of the tiling options won't tile it for a specific instance, they tile it along the entire screen, so everything using that bitmap ends up having one big bitmap tiling along all of them at the same time, without scrolling or anything.
Any ideas? If you need more info let me know, its kind of a weird question so I know I probably didn't mention something important.
William
There are a couple ways that you can attack this. I'll outline two of them here...
One way:
You can define a BitmapDrawable around the Bitmap. Set its TileMode to repeat. Give it some bounds via setBounds(rect) where rect is your Rect instance.
Here's a brief example using a View onDraw as context:
public class MyView extends View {
Rect rect;
Bitmap mBitmap;
BitmapDrawable mDrawable;
public MyView(Context context) {
super(context);
rect = new Rect(0, 0, 100, 100);
mBitmap = loadBitmap();
mDrawable = new BitmapDrawable(context.getResources(), mBitmap);
mDrawable.setTileModeXY(TileMode.REPEAT, TileMode.REPEAT);
mDrawable.setBounds(rect);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
mDrawable.draw(canvas);
}
public Bitmap loadBitmap() {
// included only for example sake
Paint paint = new Paint();
paint.setColor(Color.RED);
Bitmap bm = Bitmap.createBitmap(10, 10, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bm);
canvas.drawRect(0,0,10,10, paint);
paint.setStyle(Style.STROKE);
paint.setColor(Color.BLUE);
canvas.drawRect(0, 0, 9, 9, paint);
return bm;
}
}
Note:
You can also define a BitmapDrawable in xml instead of doing it in code.
Also, if you know that a drawable you are loading via getResources().getDrawable(resourceId) is indeed just a Bitmap, you can cast it to a BitmapDrawable and set the TileMode there. A la:
public class MyView extends View {
Rect rect;
BitmapDrawable mDrawable;
public MyView(Context context) {
super(context);
rect = new Rect(0, 0, 400, 240);
mDrawable = (BitmapDrawable) context.getResources().getDrawable(R.drawable.ic_launcher);
mDrawable.setTileModeXY(TileMode.REPEAT, TileMode.REPEAT);
mDrawable.setBounds(rect);
this.setBackgroundDrawable(context.getResources().getDrawable(R.drawable.ic_launcher));
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
mDrawable.draw(canvas);
}
}
This example shows the background being stretched, and a tiled version being draw over top of it.
Another way:
Loop in the x and y direction and repeatedly draw the bitmap into the rect:
public class MyView extends View {
Rect rect;
Bitmap mBitmap;
public MyView(Context context) {
super(context);
rect = new Rect(0, 0, 100, 100);
mBitmap = loadBitmap();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
final int bmWidth = mBitmap.getWidth();
final int bmHeight = mBitmap.getHeight();
for (int y = 0, height = rect.height(); y < height; y += bmHeight) {
for (int x = 0, width = rect.width(); x < width; x += bmWidth) {
canvas.drawBitmap(mBitmap, x, y, null);
}
}
}
public Bitmap loadBitmap() {
// included only for example sake
Paint paint = new Paint();
paint.setColor(Color.RED);
Bitmap bm = Bitmap.createBitmap(10, 10, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bm);
canvas.drawRect(0,0,10,10, paint);
paint.setStyle(Style.STROKE);
paint.setColor(Color.BLUE);
canvas.drawRect(0, 0, 9, 9, paint);
return bm;
}
}
I personally would go for the first (BitmapDrawable) method.
You can do it just like BitmapDrawable does:
Define Paint with bitmap shader and then draw rectangle with that paint:
> Paint paint = new Paint();
> paint.setShader(new BitmapShader(bitmap, Shader.TileMode.REPEAT, Shader.TileMode.REPEAT));
>
> canvas.drawRect(destRect, paint);
Can any body tell me to erase the paint on the image , in my application i was prepared the finger painting on image, if i want erase the paint it,s getting black color on image instead of erasing the image. my code is
public class MyView extends View {
int bh = originalBitmap.getHeight();
int bw = originalBitmap.getWidth();
public MyView(Context c) {
super(c);
//mBitmap = Bitmap.createScaledBitmap(originalBitmap,bw,bh,true);
mBitmap = Bitmap.createBitmap(bw,bh,Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
}
public MyView (Context c, int color) {
super(c);
mBitmap = Bitmap.createScaledBitmap(originalBitmap,bw,bh,true);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mBitmapPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC)) ;
mCanvas.drawColor(color);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
/*mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);*/
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(Color.TRANSPARENT);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
for paint erase
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
You should draw on a transparent custom view placed over the original bitmap instead of modifying the orignal. That will keep it simple.
For that you can do
<RelativeLayout ....>
<ImageView ......set original bitmap to this/>
<CustomView ...... draw on this, you can erase too./>
</RelativeLayout>
For getting the modified bitmap call the getDrawingCache() method on that RelativeLayout. That will give you the combined bitmap image.
Hope this helps.
define a temporary bitmap and canvas, then draw canvas on that temporary bitmap and pass that bitmap to onDraw your work will be done,