Virtual SelectBox

The virtual SelectBox acts like the SelectBox, but is based on the framework's virtual infrastructure.

Preview Image

widget/virtualselectbox.png

Features

  • Pointer and keyboard support.
  • Items with plain text and/or icons
  • Ellipsis: If the label does not fit into the widget's bounds an ellipsis (”...”) is rendered at the end of the label.
  • Supports filtering, sorting, grouping, data binding and custom rendering like the Virtual List.

Pointer and keyboard behavior:

       
  keyboard open drop-down key down; key up; space; enter
    close drop-down esc; enter
  pointer open drop-down tap on widget
    close drop-down tap on item; tap outside drop-down
drop-down closed keyboard select next not possible
    select previous not possible
    select first not possible
    select last not possible
  pointer select next not possible
    select previous not possible
drop-down open keyboard select next key down then enter
    select previous key up then enter
    select first page up then enter
    select last page down then enter
  pointer select next tap on item
    select previous tap on item
    wrap in list no
    preselect pointer over; key up; key down
    select drop-down item on open yes

Description

The qx.ui.form.VirtualSelectBox is based on the virtual infrastructure. It can be used to select one item and uses the Virtual List as a drop-down.

Using the virtual infrastructure has considerable advantages when there is a huge amount of model items to render: Widgets are created only for visible items and reused. This saves both creation time and memory.

The virtual SelectBox uses the same qx.ui.list.core.IListDelegate interface as the Virtual List to configure the SelectBox's behavior (item and group renderer configuration, filtering, sorting, grouping, etc.).

Note

At the moment we only support widget based rendering for list and group items, but we are planning to also support HTML based rendering in a future release.

Code Example

Here's an example. We create a simple SelectBox example with 2500 items, sort the items (ascending), select the 20th item and log each selection change.

//create the model data
var rawData = [];
for (var i = 0; i < 2500; i++) {
  rawData[i] = "Item No " + i;
}
var model = qx.data.marshal.Json.createModel(rawData);

//create the SelectBox
var selectBox = new qx.ui.form.VirtualSelectBox(model);

//configure the SelectBox's behavior
var delegate = {
  sorter : function(a, b) {
    return a > b ? 1 : a < b ? -1 : 0;
  }
};
selectBox.setDelegate(delegate);

//Pre-Select "Item No 20"
selectBox.getSelection().push(model.getItem(20));

//log selection changes
selectBox.getSelection().addListener("change", function(e) {
  this.debug("Selection: " + selectBox.getSelection().getItem(0));
}, this);

Demos

Here are some links that demonstrate the usage of the widget:

API

Here is a link to the API of the widget:
qx.ui.form.VirtualSelectBox
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