Module rule_line 

Rule line widgets and properties.

A rule line is a horizontal or vertical separator line, this module provides 3 widgets the RuleLine! base that can dynamically change orientation and the hr::Hr! and vr::Vr! that represents each orientation and can be styled separately.

use zng::prelude::*;

Window! {
    context_menu = ContextMenu!(ui_vec![
        Button!(zng::app::NEW_CMD.scoped(WINDOW.id())),
        Button!(zng::app::OPEN_CMD.scoped(WINDOW.id())),
        Hr!(),
        Button!(zng::app::EXIT_CMD),
    ]);
}

The example above uses the Hr! widget in a context menu to separate the commands into two groups.

Collapse Scope

Sometimes two or more separator lines can end-up appearing adjacent to one another, not actually separating anything. A parent panel widget can set collapse_scope to automatically trim or merge separator lines in its descendants.

The ContextMenu!, Menu! and SubMenu! widgets enable this feature by default, the standalone property can also be set in any other widget.

Wrap! {
    id = "toolbar";
    zng::rule_line::vr::height = 1.em();
    zng::rule_line::collapse_scope = true;
    children = ui_vec![
        Button!(zng::app::OPEN_CMD.scoped(WINDOW.id())),
        Vr!(),
        Button!(zng::clipboard::COPY_CMD.scoped("content")),
        Button!(zng::clipboard::PASTE_CMD.scoped("content")),
    ];
}

The example above defines a "toolbar" panel with a vertical separator, command buttons are not visible when the command has no handle, in the example the clipboard commands are scoped to a "content" target, if that widget does not exist the buttons will collapse so the Vr!() would appear dangling at the end. In this example toolbar enables all features of collapse_scope that includes CollapseMode::TRIM_END, so the vertical line will collapse as well, until the "content" widget is loaded.

Note that collapse_scope also works in nested panels, a more complex toolbars setup can enable it at the toolbar tray root widget and all toolbar widgets can be dynamically moved and the separator lines will collapse as needed. The algorithm only considers leaf descendants so the scope UI tree can have any number of nested children widgets too.

Full API

See zng_wgt_rule_line for the full widget API.

Modules

hr

Horizontal rule line widget and properties.

vr

Vertical rule line widget and properties.

Structs

CollapseMode

Represents what rule lines are collapsed in a collapse_scope.

RuleLine

W Draws a horizontal or vertical rule line.

Functions

collapse_scope

P Collapse adjacent descendant rule lines.

collapse_skip

P Defines if this widget and descendants are ignored by collapse_scope.