Edit policies
For simple text editing of cell values, an application need only provide simple beginEditCallback and endEditCallback handlers. In some advanced applications, simple text editing of a cell might not be sufficient. In these situations, the application can specify an edit policy in the callData of the beginEditCallback.
The edit policy defines the type of widget to be used for editing and some other edit semantics. The default edit policy is EwTextEditPolicy set up to use a single-line CwText as the edit widget. The application can substitute a more appropriate edit policy. For example, if the cell contains a day of the week, the application might wish to use an EwComboBoxEditPolicy. Applications can define custom edit policies by subclassing EwEditPolicy as required. The supplied subclasses of EwEditPolicy serve as good examples of this.
The following edit policies are provided in the Extended Widgets subsystem:
A cell is edited using a combo box. An application can specify the list of items to choose from and the initial value. It can also specify whether users can edit the value manually or just choose one of the items in the list.
A cell is edited using a text widget. An application can specify whether the widget is to be single or multiple lines, what the initial text value should be, what the initially selected text should be, and what the maximum length should be.
A cell is edited using a toggle button. An application can specify the label string for the toggle button, the horizontal alignment of the label string and whether or not the toggle should be initially selected.
The EwTextEditPolicy and EwComboBoxEditPolicy cancel an edit operation when the ESC key is pressed. When an edit operation is cancelled, the endEditCallback is activated using the item's old value as the edited value.
Last modified date: 01/29/2015