Split view

ui.Split lays out two panes side by side, with a divider between them that the user drags to resize them, or moves with the arrows once it has the keyboard focus: a *float32 is the width of the first, which the divider keeps 40 DIPs from either edge. When the window leaves less room than that, the first pane gives way so the second keeps its 40 DIPs, and the first takes its size back when there is room again; the *float32 keeps the size the user chose. Changed reports a move.

ui.Split(c, &app.sidebarWidth, func() { app.files(c) }, func() { app.editor(c) }).Fill()

ui.SplitVertical puts the first above the second, the *float32 its height:

ui.SplitVertical(c, &app.consoleHeight, func() { app.editor(c) }, func() { app.console(c) }).Grow(1)

ui.SplitPercent and ui.SplitVerticalPercent take the percentage of the room the first pane takes instead, from 0 to 100: both panes then grow and shrink with the window, in proportion, as a results panel under an editor does.

ui.SplitVerticalPercent(c, &app.editorPercent, func() { app.editor(c) }, func() { app.results(c) }).Grow(1)

Keep the size in the app's state, and save it to restore the layout when the app starts again. The pointer shows a resize cursor over the divider.

SplitReset makes a double click on the divider put the first pane back at the size the app chooses, in the split's own unit: DIPs for Split and SplitVertical, a percentage for the percent variants. A split without it keeps its size on a double click. The size is kept even when the window is too small to show it, so the pane takes it back when there is room again, as a press on the divider does.

ui.Split(c, &app.sidebarWidth, func() { app.files(c) }, func() { app.editor(c) }).SplitReset(220).Fill()

Accessibility

Assistive technology sees the divider as a splitter named "Divider", which takes the focus and moves with the arrows.