Class FocusModel

The FocusModel class is an implementation of the FocusModelIf interface. It provides core functionality to manage focus inside a data grid or spreadsheet-like structure. The focus can be set to a specific cell or to the whole row. This class also maintains a list of EventFocusChangedListenerIf instances and notifies them whenever there is a change in focus.

Instance Properties:

• selectionType: FocusType — Specifies the type of selection that is currently in focus. It could be either a specific cell or the whole row. Defaults to "none".
• rowIndex: number — Specifies the row index of the cell that is currently in focus.
• columnIndex: number — Specifies the column index of the cell that is currently in focus.
• listenerArr: EventFocusChangedListenerIf[] — An array of EventFocusChangedListenerIf instances. These instances will be triggered when the focus changes.
• changed — A boolean flag to check if the focus has changed since the last trigger.

Instance Methods:

• getEventFocusChangedListeners — Returns an array of EventFocusChangedListenerIf instances.
• addEventFocusChangedListener(listener: EventFocusChangedListenerIf): void — Adds a listener to the listeners array, if it's not already present.
• removeEventFocusChangedListener(listener: EventFocusChangedListenerIf): void — Removes a listener from the listeners array.
• clear: void — Clears the current focus.
• setFocus(rowIndex: number, columnIndex: number): void — Sets focus on a given cell.
• hasChanged(): boolean — Checks if the focus has changed.
• clearChanged: void — Clears the changed flag.
• hasFocus(rowIndex: number, columnIndex: number): boolean — Checks if a given cell is in focus.
• getFocus(): [number, number] — Returns the row and column indexes of the cell that's currently in focus.

Usage Example

class MyFocusChangeListener implements EventFocusChangedListenerIf {
 onFocusChanged(model: FocusModelIf): void {
   console.log('Focus changed: ', model.getFocus());
 }
}
let focusModel = new FocusModel("cell");
focusModel.addEventFocusChangedListener(new MyFocusChangeListener());
focusModel.setFocus(2, 3);
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See

• FocusType
• EventFocusChangedListenerIf

Implements