Rotate ImageView in widget
I'm creating a widget where I need to rotate an ImageView. The ImageView resides insides a layout which in turn is described in a RemoteView. Is this possible? In my regular application Activity gained a reference to the ImageView using findViewById() and then calling setRotate(), but as RemoteView isn't an activity findViewById() isn't available.
I can see that it has been done before in this app: https://开发者_如何学编程market.android.com/details?id=com.lanteanstudio.compass
If you are using RemoteViews
, then you cannot directly change the visible View itself, as there is no way of getting a reference to it -- a RemoteViews
object generally runs in a different process (in the case of the widgets on the Homescreen this is true - the widgets run in the Homescreen process, not your own).
Instead you need to create a new RemoteViews with the image rotated - you need to rotate the bitmap before setting it to the ImageView
.
Then get an instance of AppWidgetManager
, and call manager.updateAppWidget(appWidgetId, remoteView)
.
After spending a day on this... I found the following code to work for my weather app widget to indicate wind direction.
R.drawable.arrow is png in my drawable folder
windDeg is an int obtained from openweathermap.org
R.id.wind_direction is an ImageView
val bmpOriginal: Bitmap = BitmapFactory.decodeResource(context.applicationContext.resources, R.drawable.arrow) val bmpResult = Bitmap.createBitmap(bmpOriginal.width, bmpOriginal.height, Bitmap.Config.ARGB_8888) val tempCanvas = Canvas(bmpResult) tempCanvas.rotate(windDeg.toFloat(), bmpOriginal.width / 2.toFloat(), bmpOriginal.height / 2.toFloat()) tempCanvas.drawBitmap(bmpOriginal, 0f, 0f, null) views.setImageViewBitmap(R.id.wind_direction, bmpResult)
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