On Sun, Jun 05, 2016 at 03:15:30PM -0400, Rena wrote: > As an application developer, my main gripes with GtkTextView have been: > > 1. The view/buffer model. I expected that the view just asks the buffer for > text, and I could supply a custom buffer object that generates text on the > fly. In reality it seems I have to use a GtkTextBuffer and fill it with the > text I want to display, and manually respond to cursor movements by > modifying the buffer. It rather defeats the purpose of having a view/buffer > model at all.
The view is not the only user of a buffer. There can be scanners that scan the buffer, to do various things such as highlighting the syntax. The buffer/view split permits in theory to have several views for the same buffer. Lazy loading of the buffer content is something separate. > 2. Difficult to compute how much text will actually fit in the view, when > varying character sizes (especially heights) are involved. This relates to > #1, since I'm not putting text into a view, I'm putting it into a buffer > which doesn't know much about how the view is going to render it. This > makes it difficult to know how much text I need to supply. (I can usually > get away with over-estimating and supplying more than enough, but then when > the cursor is moved down at the bottom of the view, it wants to scroll, so > I have to handle that... also I hadn't even thought until now about what > "select all, copy" will do in this case.) I don't think GtkTextBuffer was meant to be used like that, despite its name. > 3. No way to control the positioning of text and/or movement of the cursor. > When implementing a hex editor widget, I wanted to display data in a format > like "00000000__00_00_00_00__00..." (where _ is a space), but have the > cursor skip over the spaces. I could find no way to achieve this except by > (again) manually handling all cursor movement events, trying to figure out > what the best valid position is for where it's trying to go, and putting it > there. I had hoped I could either tag the spaces to say "have the cursor > skip over this", or add a "margin-right" attribute to the digits like I > would in a web page, so that spaces would be added without using an actual > space character. (Although in the latter case I'd have to have a custom > "copy" handler that renders the text *with* spaces for the clipboard, so > that might not be so good either.) I think it's possible to implement virtual spaces with a utility class. It's probably not straightforward, but it should be feasible. I also need virtual spaces in gCSVedit: https://sourceforge.net/projects/gcsvedit/ -- Sébastien _______________________________________________ gtk-devel-list mailing list gtk-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-devel-list
