Editing VectorDrawable Groups From Code

Question

Editing VectorDrawable Groups From Code

Nathan Sokalski 4,111

I have a Drawable Resource containing a VectorDrawable that contains several Group(s). I need to edit one of these Group(s) from code. I am able to create the new Path(s) I need, but I am not sure how to remove the Path(s) already in the Group or how to add the new ones. How can I edit the Group(s) in my VectorDrawable from code?

JarvanZhang 23,971 Reputation points

2021-12-13T09:29:10.037+00:00

Hi, njsokalski. We cannot edit the parameter of the VectorDrawable xml in code. The VectorDrawable xml is converted by a vector graphic, changing the properties is the xml may cause the graphic doesn't work. And VectorDrawable class doesn't provide the related method to modify the drawable.

Similar issue thread: https://stackoverflow.com/questions/37023687/how-do-i-set-a-group-parameter-of-vector-drawable-programmatically

If you want to update the animation, please try to use a different vector drawable xml instead.
Nathan Sokalski 4,111 Reputation points

2021-12-14T04:16:01.767+00:00
I decided to try creating a custom view that adds the paths to the canvas passed to the OnDraw method. However, when doing this, I am having trouble getting the view to scale to the full available space like I did when I had it as a resource. I previously used the following XML:

<ImageView android:visibility="gone" android:id="@+id/imgColorSpinner" android:layout_width="wrap_content" android:layout_height="0dp" android:layout_column="0" android:layout_row="1" android:layout_rowWeight="1" android:src="@drawable/colorspinner" android:layout_marginLeft="5dp" android:layout_marginRight="5dp" android:scaleType="fitCenter" android:layout_gravity="fill"/>

Note that this uses the scaleType property, which is not available when inheriting from View. Is there a way to get a custom view to scale the way ImageView did?
JarvanZhang 23,971 Reputation points

2021-12-14T08:39:04.273+00:00

Could you please post the related code about the 'OnDraw' method of the custom view class? Try to override the OnSizeChanged event to re-caculate the size value. You could refer to this thread: https://stackoverflow.com/a/55269742/11083277
Nathan Sokalski 4,111 Reputation points

2021-12-14T17:59:35.283+00:00

The OnDraw method simply calls canvas.DrawPath(...) several times to draw the custom view. OnSizeChanged sounds like it could be useful, but I am not quite sure how to determine the available space or how to the desired alignment. My goal is to stretch the view to the maximum size while keeping the same width/height ratio, and align it horizontally centered or vertically to the top (whichever the case may be). Is there a way to do this in OnSizeChanged?
JarvanZhang 23,971 Reputation points

2021-12-15T07:54:27.073+00:00

My goal is to stretch the view to the maximum size while keeping the same width/height ratio

Canvas provides the ‘Scale’ method, try using the method to scale the canvas after drawing the path.