Skip to content

Instantly share code, notes, and snippets.

@arriolac

arriolac/DrawingViewArchitecture.md

Created September 7, 2015 16:57
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save arriolac/fd2431ab5e8c1cd9fac3 to your computer and use it in GitHub Desktop.
Save arriolac/fd2431ab5e8c1cd9fac3 to your computer and use it in GitHub Desktop.
Download ZIP
DrawingView Architecture
Raw
DrawingViewArchitecture.md

This is the proposed architecture for implementing drawing on text, photos and videos on Leo.

DrawingView

  • This is the custom view that will display the drawing created by the user.
  • Will be the View on "top" (relative to z-axis) of all the other views in AddTextActivity except the top bar Views.
  • Notes:
    • overrides onTouchEvent(...)
    • has a method called setEnabled(boolean enabled)
      • enabled value will be returned by onTouchEvent(...). this means that it will intercept all touch events when enabled.
      • Note: this will be toggled by the compose views (enabled when in drawing mode, disabled when not in drawing mode).
    • has a setColor(...) method
    • contains a transcript (LinkedList) of "drawing events" (I think these "drawing events" will be Path objects)
    • has an undo function that removes the last drawn event from the canvas (head of the LinkedList)
    • Look at the FingerPaint sample app in the API demos to see how to draw to canvas given a sequence of touch points.
  • Create a screenshot (Bitmap) of the composition by calling View.getDrawingCache(). The screenshot should not include the EditText, top & bottom bar views. This means getDrawingCache() should only be called on the ViewGroup that contains the ImageView + DrawingView.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment