2009-06-13

Cursors, Text Boxes and Other Changes

Some minor Woopsi news. The ListBox removes itself from its ListData object’s list of event handlers when it gets deleted. This is slightly redundant at the moment, as the ListData object is internal within the ListBox and will therefore be deleted once its owner is deleted. However, it’s possible that I’ll allow the ListData class to be defined outside of the ListBox eventually, so this change does make sense in that scenario.

The DimmedScreen is now an “official” gadget. Since I’ve moved all of the dimming code into the GraphicsPort, the DimmedScreen only contains about a dozen lines of code, but creating the dimmed effect requires some knowledge of exactly how Woopsi’s drawing/erasing systems work. Due to this (plus the fact that it’s a neat trick, and isn’t hacky any more) it made sense to promote the DimmedScreen from bonus gadget to official gadget.

Lastly, I’m starting to finish off the cursor support in the text boxes. When the TextBox or MultiLineTextBox gadgets have focus, pressing left or right on the d-pad causes the cursor to move. There are a couple more changes to be made to the MultiLineTextBox:

  • Pressing up or down on the d-pad needs to move the cursor up or down a row;
  • Tapping on the text box with the stylus needs to cause the cursor to jump to the stylus location.

Both of these are rendered slightly more complex due to the MultiLineTextBox’s support for different alignment styles.

I’ve also got a few alignment bugs to fix in the MultiLineTextBox, too. Once these are done, I’m not sure there’s anything left to do. I’ve got all of the gadgets created that I wanted to, the event system is tidier and working (note to self - do I need to refactor the radio button group’s event system?), and I can’t think of any other outstanding bugs. I should probably have made a to-do list before I got distracted by my exam revision (provisional average grade is just over 80%, which should put me well into the “distinction” category - hurrah!).

The next steps will be documenting and testing Woopsi, as well as writing plenty of example programs.

2008-10-31

Cursors and Bitmaps

Two changes today. I’ve optimised the MultiLineTextBox’s cursor drawing routines. It’s not as fast as it could be - the fastest way to draw it would probably be to inject it into the main drawText() routine - but as that class changes so much I think it’s best to keep it readable at this stage.

Secondly, I’ve replaced the Bitmap struct with a Bitmap class. The struct wasn’t being used anywhere. The class includes all of the drawing functionality previously only available in the SuperBitmap, so it is now possible to create and manipulate bitmaps entirely in memory without an associated gadget. This should, I think, answer one of Jeff’s earlier queries. I’ll get around to stripping the code from the SuperBitmap and replacing it with the Bitmap class later. Not sure if the SuperBitmap is going to inherit from the Bitmap or just contain an instance of it yet.