android-canvas

I would like to use Canvas.drawText() to display multi-color text. More specifically, I want to highlight a substring of the text passed to the drawText() method. The text is in the form of a SpannableString with 0 or more ForegroundColorSpan objects. Looking at the Canvas code, it appears that a .toString() call on the passed CharSequence, means that this is not possible. Is there an alternative way? EDIT: The text may occasionally change (total changes, not incremental). Also, there are potentially multiple texts positioned in different unrelated locations in the custom view. Renard Yes it

Im using below code to draw line on bitmap canvas while finger touch move... here i posted partial code and it is working fine.. As shown in below image, the black and white bitmap erased on touch drag.. I made canvas transparent so the parent layout background(color image) is getting visible. I want to know , how much area is erased(like 50% or 60% of bitmap ).. is there any way to find that? //Erasing paint mDrawPaint = new Paint(); mDrawPaint.setAntiAlias(true); mDrawPaint.setDither(true); mDrawPaint.setStyle(Paint.Style.STROKE); mDrawPaint.setStrokeJoin(Paint.Join.ROUND); mDrawPaint

I am a fairly "newb" Android developer, and I would like one of my first projects to be a live wallpaper, however I am conflicted on whether I should be focusing on Canvas or OpenGL for it. Being new to this I know I should master Canvas first since it is easier to use, but I prefer to learn from real world projects that I have an interest in, even if it's a little backwards at times. I have used both before in very basic ways, and I understand the general concepts to them, but I am not sure how they transfer over to the realm of live wallpapers. I figure that the full blown speed of OpenGL

I am trying to allow the user to touch the image and then basically a cirular magnifier will show that will allow the user to better select a certain area on the image. When the user releases the touch the magnified portion will dissapear. This is used on several photo editing apps and I am trying to implement my own version of it. The code I have below does magnify a circular portion of the imageview but does not delete or clear the zoom once I release my finger. I currently set a bitmap to a canvas using canvas = new Canvas(bitMap); and then set the imageview using takenPhoto.setImageBitmap

This is how I draw Bitmap on Canvas in my Android app: canvas.save(); canvas.scale(scale, scale, x, y); canvas.drawBitmap(bitmap, x, y, null); canvas.restore(); However the Bitmap is not scaled smoothly, no anti-aliasing is performed. How can I enable anti-aliasing? Try this: Paint paint = new Paint(); paint.setAntiAlias(true); paint.setFilterBitmap(true); paint.setDither(true); canvas.drawBitmap(bitmap, x, y, paint); Sileria Both Paint paint = new Paint(Paint.FILTER_BITMAP_FLAG); or paint.setFilterBitmap(true); worked for me but be very careful, on my game it cut down the FPS from 30FPS to

Is there a method which returns the width ( in pixels ) of a text to be drawn on an Android canvas using the drawText() method according to the Paint used to draw it? Have you looked at android.graphics.Paint.measureText(String txt) ? hamid reza zavareh Paint paint = new Paint(); Rect bounds = new Rect(); int text_height = 0; int text_width = 0; paint.setTypeface(Typeface.DEFAULT);// your preference here paint.setTextSize(25);// have this the same as your text size String text = "Some random text"; paint.getTextBounds(text, 0, text.length(), bounds); text_height = bounds.height(); text_width =