NSControl Class Reference

Discussion

If there was a field editor, this method removes the field editor’s delegate.

Discussion

The NSControl implementation of this method returns the action message selector of the receiver's cell. Controls that support multiple cells (such as NSMatrix and NSForm) must override this method to return the appropriate action-message selector.

If you want the action-message selector for a control that has multiple cells, it is better to use the get the selector directly from the cell's own action method, as shown in the following example:

SEL someAction = [[theControl selectedCell] action];

Discussion

Expansion tooltips are shown when the cell can not show the full content and the user hovers over the control with the mouse. This is controlled by the NSCell class method expansionFrameWithFrame:inView: and is drawn by drawWithExpansionFrame:inView:. This value is encoded along with the control.

In general, it is recommended to turn this on for NSTextField instances in a view-based NSTableView.

The default value is NO.

Discussion

If the control contains many cells (for example, NSMatrix), then the value of the currently selected cell is returned. If the control is in the process of editing the affected cell, then it invokes the validateEditing method before extracting and returning the value.

Discussion

The Text system uses this value as a hint for calculating the actual direction for displaying Unicode characters. You should not need to call this method directly.

Discussion

This method uses the calcDrawInfo: method of its cell to perform the calculations. Most controls maintain a flag that informs them if any of their cells have been modified in such a way that the location or size of the cell should be recomputed. If such a modification happens, this method is automatically invoked before the control is displayed. You should never need to invoke it yourself.

Discussion

For controls with multiple cells (such as NSMatrix or NSForm), use the selectedCell method or a similar method to retrieve a specific cell.

Discussion

When the receiver is a control displaying editable text (for example, a text field) and it is the first responder, it has a field editor, which is returned by this method. The field editor is a single NSTextView object that is shared among all the controls in a window for light text-editing needs. It is automatically instantiated when needed.

Discussion

If the control contains many cells (for example, NSMatrix), then the value of the currently selected cell is returned. If the control is in the process of editing the affected cell, then it invokes the validateEditing method before extracting and returning the value.

Discussion

This method is provided primarily to support a consistent set of methods between NSControl objects with single and multiple cells, because a control with multiple cells needs to be able to draw individual cells.

Discussion

If the receiver is transparent, the method causes the superview to draw itself. This method invokes the drawInteriorWithFrame:inView: method of NSCell. This method has no effect on controls (such as NSMatrix and NSForm) that have multiple cells.

Discussion

If the control contains many cells (for example, NSMatrix), then the value of the currently selected cell is returned. If the control is in the process of editing the affected cell, then it invokes the validateEditing method before extracting and returning the value.

Discussion

If a cell has been specified for controls of this type, this method also creates an instance of the cell. Because NSControl is an abstract class, invocations of this method should appear only in the designated initializers of subclasses; that is, there should always be a more specific designated initializer for the subclass, as this method is the designated initializer for NSControl.

Discussion

If the control contains many cells (for example, NSMatrix), then the value of the currently selected cell is returned. If the control is in the process of editing the affected cell, then it invokes the validateEditing method before extracting and returning the value.

Discussion

If the control contains many cells (for example, NSMatrix), then the value of the currently selected cell is returned. If the control is in the process of editing the affected cell, then it invokes the validateEditing method before extracting and returning the value.

Discussion

Controls determine their intrinsic content size based on the cell size for a given bounds returned by their cell. When the content of the cell changes in a way that would change the return value of cellSizeForBounds:, the cell needs to call this method to notify its control that its intrinsic size is no longer valid.

Discussion

Invoked when the mouse button is pressed while the cursor is within the bounds of the receiver, generating theEvent. This method highlights the receiver’s cell and sends it a trackMouse:inRect:ofView:untilMouseUp: message. Whenever the cell finishes tracking the mouse (for example, because the cursor has left the cell’s bounds), the cell is unhighlighted. If the mouse button is still down and the cursor reenters the bounds, the cell is again highlighted and a new trackMouse:inRect:ofView:untilMouseUp: message is sent. This behavior repeats until the mouse button goes up. If it goes up with the cursor in the control, the state of the control is changed, and the action message is sent to the target. If the mouse button goes up when the cursor is outside the control, no action message is sent.

Discussion

If the control contains many cells (for example, NSMatrix), then the value of the currently selected cell is returned. If the control is in the process of editing the affected cell, then it invokes the validateEditing method before extracting and returning the value.

Discussion

This method calls the performClick: method of the receiver's cell with the sender being the control itself. This method raises an exception if the action message cannot be successfully sent.

Discussion

If the cell is already selected (or does not belong to the receiver), this method does nothing. If the cell belongs to the receiver and is not selected, this method changes its state to NSOnState and redraws the cell.

Discussion

The default implementation of this method simply returns the control's associated cell (or nil if no cell has been set). Subclasses of NSControl that manage multiple cells (such as NSMatrix and NSForm) must override this method to return the cell selected by the user.

Discussion

When you set the tag of a control with a single cell in Interface Builder, it sets the tags of both the control and the cell with the same value as a convenience.

Discussion

This method uses the sendAction:to:from: method of NSApplication to invoke the specified method on an object. The receiver is passed as the parameter to the action message. This method is invoked primarily by the trackMouse:inRect:ofView:untilMouseUp: method of NSCell.

Discussion

You use this method during mouse tracking when the mouse button changes state, the mouse moves, or if the cell is marked to send its action continuously while tracking. Because of this, the only bits checked in mask are NSLeftMouseDownMask, NSLeftMouseUpMask, NSLeftMouseDraggedMask, and NSPeriodicMask, which are declared in the NSEvent class reference.

The default implementation of this method simply invokes the sendActionOn: method of its associated cell.

Discussion

If the cell is currently being edited, this method aborts the edits to change the alignment.

Discussion

Expansion tooltips are shown when the cell can not show the full content and the user hovers over the control with the mouse. This is controlled by the NSCell class method expansionFrameWithFrame:inView: and is drawn by drawWithExpansionFrame:inView:. This value is encoded along with the control.

In general, it is recommended to turn this on for NSTextField instances in a view-based NSTableView.

The default value is NO.

Discussion

If the cell is being edited, this method aborts all editing before setting the value. If the cell does not inherit from NSActionCell, the method marks the cell’s interior as needing to be redisplayed; NSActionCell performs its own updating of cells.

Discussion

If you know the base writing direction of the text you are rendering, you can use this method to specify that direction to the text system.

Discussion

Use this method with great care as it can irrevocably damage the affected control; specifically, you should only use this method in initializers for subclasses of NSControl.

Discussion

If the cell is being edited, this method aborts all editing before setting the value. If the cell does not inherit from NSActionCell, the method marks the cell’s interior as needing to be redisplayed; NSActionCell performs its own updating of cells.

Discussion

If flag is NO, any editing is aborted. This method redraws the entire control if it is marked as needing redisplay. Subclasses may want to override this method to redraw only a portion of the control when the enabled state changes; NSButton and NSSlider do this.

Discussion

If the cell is being edited, this method aborts all editing before setting the value. If the cell does not inherit from NSActionCell, the method marks the cell’s interior as needing to be redisplayed; NSActionCell performs its own updating of cells.

Discussion

If the cell is being edited, the text in the cell is redrawn in the new font, and the cell’s editor (the NSText object used globally for editing) is updated with the new font object.

Discussion

By default, controls treat double clicks as two distinct clicks, triple clicks as three distinct clicks, and so on. However, if you pass YES to this method, additional clicks (within a predetermined interval after the first) occurring after the first click are not processed by the receiver, and are instead passed on to super.

Discussion

If the cell is being edited, this method aborts all editing before setting the value. If the cell does not inherit from NSActionCell, the method marks the cell’s interior as needing to be redisplayed; NSActionCell performs its own updating of cells.

Discussion

If the cell is being edited, this method aborts all editing before setting the value. If the cell does not inherit from NSActionCell, the method marks the cell’s interior as needing to be redisplayed; NSActionCell performs its own updating of cells.

Discussion

This method also recalculates the dimensions of the control as needed.

Discussion

If the cell is being edited, this method aborts all editing before setting the value. If the cell does not inherit from NSActionCell, the method marks the cell’s interior as needing to be redisplayed; NSActionCell performs its own updating of cells.

Discussion

By default, the user can advance the focus of keyboard events between controls by pressing the Tab key; when this focus—or first responder status—is indicated for a control (by the insertion point or, for nontext controls, a faint rectangle), the user can activate the control by pressing the Space bar.

Discussion

If the cell is being edited, this method aborts all editing before setting the value. If the cell does not inherit from NSActionCell, the method marks the cell’s interior as needing to be redisplayed; NSActionCell performs its own updating of cells.

Discussion

This method does not affect the tag of the receiver’s cell. Tags allow you to identify particular cells. Tag values are not used internally; they are only changed by external invocations of setTag:. You typically set tag values in Interface Builder and use them at runtime in your application. When you set the tag of a control with a single cell in Interface Builder, it sets the tags of both the control and the cell to the same value as a convenience.

Discussion

If anObject is nil but the control still has a valid action message assigned, the application follows the responder chain looking for an object that can respond to the message. See the description of the NSActionCell class for details.

Discussion

If you want a multiple-cell custom subclass of NSControl to size itself to fit its cells, you must override this method. This method neither redisplays the receiver nor marks it as needing display. You must do this yourself with either thedisplay or setNeedsDisplay method.

Discussion

If the control contains many cells (for example, NSMatrix), then the value of the currently selected cell is returned. If the control is in the process of editing the affected cell, then it invokes the validateEditing method before extracting and returning the value.

Discussion

Tags allow you to identify particular controls. Tag values are not used internally; they are only changed by external invocations of setTag:. You typically set tag values in Interface Builder and use them at runtime in your application. When you set the tag of a control with a single cell in Interface Builder, it sets the tags of both the control and the cell to the same value as a convenience.

Discussion

You can use this method to link action messages between controls. It permits one control or cell (sender) to affect the value of another control (the receiver) by invoking this method in an action message to the receiver. For example, a text field can be made the target of a slider. Whenever the slider is moved, it sends this message to the text field. The text field then obtains the slider’s value, turns it into a text string, and displays it.

Discussion

You can use this method to link action messages between controls. It permits one control or cell (sender) to affect the value of another control (the receiver) by invoking this method in an action message to the receiver. For example, a text field can be made the target of a slider. Whenever the slider is moved, it sends this message to the text field. The text field then obtains the slider’s value, turns it into a text string, and displays it.

Discussion

You can use this method to link action messages between controls. It permits one control or cell (sender) to affect the value of another control (the receiver) by invoking this method in an action message to the receiver. For example, a text field can be made the target of a slider. Whenever the slider is moved, it sends this message to the text field. The text field then obtains the slider’s value, turns it into a text string, and displays it.

Discussion

You can use this method to link action messages between controls. It permits one control or cell (sender) to affect the value of another control (the receiver) by invoking this method in an action message to the receiver. For example, a text field can be made the target of a slider. Whenever the slider is moved, it sends this message to the text field. The text field then obtains the slider’s value, turns it into a text string, and displays it.

Discussion

You can use this method to link action messages between controls. It permits one control or cell (sender) to affect the value of another control (the receiver) by invoking this method in an action message to the receiver. For example, a text field can be made the target of a slider. Whenever the slider is moved, it sends this message to the text field. The text field then obtains the slider’s value, turns it into a text string, and displays it.

Discussion

You can use this method to link action messages between controls. It permits one control or cell (sender) to affect the value of another control (the receiver) by invoking this method in an action message to the receiver. For example, a text field can be made the target of a slider. Whenever the slider is moved, it sends this message to the text field. The text field then obtains the slider’s value, turns it into a text string, and displays it.

Discussion

If the cell currently has the focus, this method updates the cell's focus ring; otherwise, the entire cell is marked as needing redisplay. The cell is redrawn during the next update cycle.

Discussion

Validation sets the object value of the cell to the current contents of the cell’s editor (the NSText object used for editing), storing it as a simple NSString or an attributed string object based on the attributes of the editor.