@@ -1,32 +1,41 @@ Design of an immediate graphical user interface api with managed layouts Terms: -1. Canvas - a drawing area with a managed layout +1. Canvas - a drawing area User stories 1. I would like to call UI-rendering functions without specifying dimensions and locations + 2. I would like to call custom UI-rendering functions while specifying dimensions and locations +/---------------------------------- Story 2 needs a way to get a proper starting location or a bounding box If 1 is in place. Consider the single method Layout interface: type Layout interface { // Advances the layout and returns a starting point // for an element based on the last ending point. - Next(Point) Point + Next(last Point) Point } Story 1 necessitates that library-aware UI-rendering functions acquire their starting locations on their own. This allows for the following two approaches (more are possible of course) * Store the ending point of the last element. New calls can get it and pass it to the layout + does not advance the layout unless required, saving cpu + + does not imply a dependency on the layout, the UI drawing needs just a starting point * Store the next starting point by calling Next() at the end of the element drawing routine. The next drawing can continue from it. - advancing the layout costs cpu - the user might want an out of layer render + - puts a dependency on the layout + +The first strategy is definatelly more sound and neatly allows for a layout-aware tracker +to handle the locations. +\---------------------------------- +3. I would like to enhance drawing functions with additional behavior (e.g. layout trackers, styling, etc)