droidcon SF 2017 - Canvas Drawing for Fun and Profit

[@0877adri]

i love this guy :-) I made seom notes, maybe useful for someone Canvas: can be used via View, Drawable or can be created from a Bitmap. Path: a cache of multiple canvas commands onChangeBounds: update Path object to new measurements canvas.clip(): the defined clipped area will not be ignored for all canvas drawings. Untill the canvas is restored to a state before the clip. Save restore: is like a big stack of undo. Like each restore goes to the previous save state in the stack. Save and restore makes it possible to just draw what u want to draw and dont worry about the positioning, as it is handled already with the rotation and translation of the canvas. If we want for example a smaller version of our drawing, we can just use canvas.scale and all our drawings become smaller. Scale: scale all future draw calls by the specified amount. Methods to save and restore: translate, rotate, clip. If Canvas is not restored it will be passed on to the next view with this modification and will brake the drawing of the next View. PathEffect: modifies how a path is drawn. ComposePathEffect: only one pathEffect can be applied, with this multiple effects can be combined. The order they are applied are from last to first.

[@mubin986]

It was a great instruction for canvas drawing. Thank you Mr. Ryan Harter

[@danielsenik2432]

will absolutely use it, if needed at some point.

[@christopherelias8022]

Great Talk! Awesome speaker, and the finale was worthy of an oscar hahaha.

[@damercy]

What an explanation. Loved it!

[@themightymemearmy8001]

Not all heroes wear capes, some of them just love donuts

[@shoaibahmad6910]

Absolutely brilliant stuff for canvas illiterates like me. Sadly there is no official documentation which helps you that much. I will apply those techniques to Flutter canvas as well.

[@caseyshaneperkins]

The clipped hole Path renders jaggedly. I can set ANTI_ALIAS_FLAG on a Paint and get a smooth circle, but if I can't draw a smooth hole in the circle, this technique is not useful.

[@kaustubhpatange]

All I took from this talk is Ryan loves his donuts!

[@subhrajyotisen7218]

Great talk!

[@lui970]

Thanks a lot!

[@iheb404-notfound3]

You Are God