Paint over the specific area in Android

Question

I want to draw over the specific Line, Rectangle or Bitmap using Canvas. If i draw over the Bitmap, it will take the square shape empty background also.

So i want to draw over that particular Bitmap area only.

you want draw a empty rectangle around the bitmap? like border? — Saeed-rz, Jul 09 '13 at 09:56
@Leon_SFS hii leon..i have to paint over the alphabet letters only in canvas..how can i do that..do you have any idea..if i using bitmap to draw,it will take the extra square shape background surface..i want to draw only over the image..can u understand this??? — karthik, Jul 09 '13 at 10:32
create a rectangle from your drawing area,then use canvas.clipRect(rect); to crop your drawing area, then use canvas.drawtext or .... to draw every thing on it — Saeed-rz, Jul 09 '13 at 10:43
@Leon_SFS sorry to ask frequently...can we clip image only from bitmap..without the empty background(like .png image)..waiting for your reply. — karthik, Jul 09 '13 at 12:01
yes,the image is shape,and have width and height,you can get the left,right,top and bottom position when draw on screen,create a rect with their position and clip it with canvas (dont be sorry,you can ask dozen question and we enjoy to answer them) — Saeed-rz, Jul 09 '13 at 12:43
@Leon_SFS Thanks Leon,by this method we will get the square or rectangle shape image only..but i want to clip the image as like as .png image.For example i have to draw alphabet letter A over the bitmap image A..but If i create the bitmap in screen or clipping the bitmap.it would appear as a .jpg square shaped background image..i need only the image without that empty background..can you get my question clearly. — karthik, Jul 09 '13 at 13:58
@Leon_SFS im working with your code but i cant draw over the bitmap only..it draw over full screen..but i need to draw only inside the bitmap. — karthik, Jul 10 '13 at 09:26
@Leon_SFS i posted a question 1 hour before i didn't get any solution. — karthik, Jul 10 '13 at 12:37

score 3 · Accepted Answer · answered Jul 09 '13 at 15:03

create a bitmap with "bmp1" name from your desire image
create a custom view
create a class and extend View like this

class MyCustomView extends View{

private Rect m_ImageRect;
private Rect m_TextRect ;

//you need these constructor
//you can init paint object or anything on them
public MyCustomView (Context context, AttributeSet attrs, int defStyle)
{
    super(context, attrs, defStyle);
    m_Context = context;

}

public MyCustomView (Context context, AttributeSet attrs)
{
    super(context, attrs);
    m_Context = context;

}

public MyCustomView (Context context)
{
    super(context);
    m_Context = context;

}

//then override on draw method
@Override
protected void onDraw(Canvas canvas)
{
    super.onDraw(canvas);
            //here frist create two rectangle
            //one for your image and two for text you want draw on it
    m_ImageRect = canvas.getClipBounds();
        m_TextRect = canvas.getClipBounds();
            //it gives you an area that can draw on it,
            //the width and height of your rect depend on your screen size device
            canvas.drawBitmap(your bitmap(bmp1), null, m_ImageRect , paint);
            canvas.save();
    canvas.clipRect(m_TextRect);

            canvas.drawText("your text", the x position you want to start draw,
            the y position you want to start draw, m_paintText);

            canvas.restore();
}
}

at the end put the custom view on your layout,and set field on it to send value to view for draw every thing you want

i hope it's help you,if this is not what you want!
post your code so maybe i can help you more

score 0 · Answer 2 · edited May 23 '17 at 11:49

0

Seems like you need clipping. See exampls: http://www.example8.com/category/view/id/15543 , Understanding Android Canvas Clipping , http://jtomlinson.blogspot.com/2008/10/clipping.html

With clipping you can specify, which regions should be 'editable'.

edited May 23 '17 at 11:49

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answered Jul 09 '13 at 09:58

Zielony

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Paint over the specific area in Android

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