traitsui编辑器的当前大小

Question

I have a tvtk SceneEditor for a mayavi scene in my traitsui application. When defining this editor, I asked it to have size 500x500.

Because of the mayavi toolbar, the scene editor itself understands that it has a smaller size than this under normal circumstances:

>>> self.scene.scene_editor.get_size()
wx.Size(500, 468)

And when the window is enlarged so that the editor takes up much more space, it understands this too

>>> self.scene.scene_editor.get_size()
wx.Size(500, 781)

However, if the editor is made much smaller, it refuses to take up less space (even if the contents could easily be rescaled) because the editor was specified to take up 500x500. It allows the editor to be resized, but just cuts off part of the display until it is enlarged again.

I want to know if there is a way to a) ask how much of the editor is currently displayed on the screen (instead of the minimum size the editor is willing to display) and b) make the editor default to 500x500 but be willing to ask its contents to rescale themselves if it is made smaller.

I am using the wxpython backend.

edit: It is also important that the scene is contained within a layout='split' Group -- after exploring this question and running into the enormous number of sizers that wx generates when adding traitsui widgets, I realized this might matter as well.

Answer 1

After hacking around for a few days, I have an answer to part a) (though it is hacky and not necessarily general purpose and it might be specific to the layout='split' layout).

self.scene.scene_editor.control.Parent.Parent.Size describes the size of the viewport in which the editor is being displayed, at least with layout='split' but I can easily imagine that it would be different for other layout types (which I didn't test).

Armed with this information, I managed to write a wrapper that resizes the editor to be at least this small before making snapshots.

More gory details:

The sizer associated with self.scene.scene_editor.control isn't the right one, probably because that sizer refers to the window containing the editor, whereas the sizer associated with the size of window within the containing splitter widget is allowed to "cover" that window and ignore its size.

I found out that the process of adding traitsui widgets defines so many boxes (assuming a nontrivial number of widgets) that there result is this enormous glut of wx Windows with their associated wx Sizers that all depend on their child widgets to determine the current size, so it is extremely difficult to control things like this. This is probably why enaml exists; so that these constraints can be explicitly specified by the user. Maybe someday I will convert my program to use enaml, but that seems like a lot of effort for something that currently works pretty well.

I still don't have an answer to part b), so I am leaving this question open. It would be nice if there were a way to specify at construction to the mess of wx sizers that resizing this window below its initial size is allowed, but there probably isn't one.