Graphics

In Giggity app a user can create a shortcut for the event by clicking on “home shortcut” button in the navigation drawer. Open Event format provides the logo URL in the return data so we do not need to provide it separately in the app’s raw file. Sometimes the image can be too big to be put on screen as icon for shortcut. In this blog I describe a very simple method to check if we should use the image or not to avoid the crash and pixelation due to resolution. We can store the image received in bitmap format. A bitmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. By storing it in bitmap format we can easily get the necessary information about the image to check if it is suitable for use. We can use the BitmapFactory class which provides several decoding methods like (decodeByteArray(), decodeFile(), decodeResource(), etc.) for creating a Bitmap from various sources. Choose the most appropriate decode method based on your image data source. These methods attempt to allocate memory for the constructed bitmap and therefore can easily result in an OutOfMemory exception. Each type of decode method has additional signatures that let you specify decoding options via the BitmapFactory.Options class. Setting the inJustDecodeBounds property to true while decoding avoids memory allocation, returning null for the bitmap object but setting outWidth, outHeight and outMimeType. This technique allows you to read the dimensions and type of the image data prior to construction (and memory allocation) of the bitmap. BitmapFactory.Options options = new BitmapFactory.Options(); options.inJustDecodeBounds = true; BitmapFactory.decodeResource(getResources(), R.id.myimage, options); int imageHeight = options.outHeight; int imageWidth = options.outWidth; String imageType = options.outMimeType; To avoid java.lang.OutOfMemory exceptions, check the dimensions of a bitmap before decoding it, unless you absolutely trust the source to provide you with predictably sized image data that comfortably fits within the available memory. So here is the particular example from Giggity app, it avoids crash on the recieving a large image for the icon. So once we store the the image in bitmap format we check if the height and width of the icon is exceeding the maximum limit. public Bitmap getIconBitmap() { InputStream stream = getIconStream(); Bitmap ret = null; if (stream != null) { ret = BitmapFactory.decodeStream(stream); if (ret == null) { Log.w("getIconBitmap", "Discarding unparseable file"); return null; } if (ret.getHeight() > 512 || ret.getHeight() != ret.getWidth()) { Log.w("getIconBitmap", "Discarding, icon not square or >512 pixels"); return null; } if (!ret.hasAlpha()) { Log.w("getIconBitmap", "Discarding, no alpha layer"); return null; } } return ret; } If it does then we can avoid the icon. In this case we check if the icon is more than 512 pixels in height and width. If it is so then we could avoid it. We could also check if the icon has a transparent background by using “hasAlpha” so…