---

QCCompositionPickerView Class Reference

Overview

The QCCompositionPickerView class allows users to browse compositions that are in the Quartz Composer composition repository, and to preview them. You can set the default input parameters for a composition preview by using the method setDefaultValue:forInputKey:.

Note that the composition picker view does not automatically refresh its content when the composition repository is updated. It’s your responsibility to perform any necessary updating.

Tasks

Setting and Getting the Background Color

• – setBackgroundColor:
• – backgroundColor

Managing Background Drawing

• – setDrawsBackground:
• – drawsBackground

Setting Composition Input Parameters

• – setDefaultValue:forInputKey:
• – resetDefaultInputValues

Managing Animation

• – startAnimation:
• – stopAnimation:
• – isAnimating
• – setMaxAnimationFrameRate:
• – maxAnimationFrameRate

Controlling Display of Composition Names

• – setShowsCompositionNames:
• – showsCompositionNames

Setting and Retrieving the View Delegate

• – setDelegate:
• – delegate

Managing the Composition Picker View

• – setCompositionsFromRepositoryWithProtocol:andAttributes:
• – compositions
• – setAllowsEmptySelection:
• – allowsEmptySelection
• – setCompositionAspectRatio:
• – compositionAspectRatio
• – setSelectedComposition:
• – selectedComposition

Working with Columns and Rows

• – setNumberOfColumns:
• – numberOfColumns
• – setNumberOfRows:
• – numberOfRows

Instance Methods

allowsEmptySelection

Retrieves the empty-selection state of the composition picker view.

- (BOOL) allowsEmptySelection

Return Value

YES if an empty selection is allowed NO otherwise.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setAllowsEmptySelection:

Declared In

QCCompositionPickerView.h

backgroundColor

Returns the background color of the composition picker view.

- (NSColor*) backgroundColor;

Return Value

The background color.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setBackgroundColor:

Declared In

QCCompositionPickerView.h

compositionAspectRatio

Retrieves the aspect ratio used to display compositions in the composition picker view.

- (NSSize) compositionAspectRatio

Return Value

The aspect ratio.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setCompositionAspectRatio:

Declared In

QCCompositionPickerView.h

compositions

Returns the list of compositions that are currently in the composition picker view.

- (NSArray*) compositions

Return Value

An array of QCComposition objects.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setCompositionsFromRepositoryWithProtocol:andAttributes:

Declared In

QCCompositionPickerView.h

delegate

Retrieves the composition picker view delegate.

- (id) delegate

Return Value

The delegate.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setDelegate:

Declared In

QCCompositionPickerView.h

drawsBackground

Returns whether the composition picker view draws its background.

- (BOOL) drawsBackground;

Return Value

YES if the composition picker view draws its background; otherwise NO.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setDrawsBackground:

Declared In

QCCompositionPickerView.h

isAnimating

Returns whether or not the composition picker view is currently animating its composition.

- (BOOL) isAnimating

Return Value

YES if a composition is animating in the composition picker view; NO otherwise.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – startAnimation:
• – stopAnimation:

Declared In

QCCompositionPickerView.h

maxAnimationFrameRate

Retrieves the maximum frame rate for animating compositions.

- (float) maxAnimationFrameRate

Return Value

The maximum frame rate.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setMaxAnimationFrameRate:

Declared In

QCCompositionPickerView.h

numberOfColumns

Retrieves the number of columns in the composition picker view.

- (NSUInteger) numberOfColumns;

Return Value

The number of columns.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setNumberOfColumns:

Declared In

QCCompositionPickerView.h

numberOfRows

Retrieves the number of rows in the composition picker view.

- (NSUInteger) numberOfRows;

Return Value

The number of columns.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setNumberOfRows:

Declared In

QCCompositionPickerView.h

resetDefaultInputValues

Clears all previously set default values for composition input parameters.

- (void) resetDefaultInputValues

Discussion

This method resets the defaults that were set with the method setDefaultValue:forInputKey:.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

QCCompositionPickerView.h

selectedComposition

Returns the composition that is currently selected in the composition picker view.

- (QCComposition*) selectedComposition

Return Value

A QCComposition object, or nil if a composition is not selected.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – setSelectedComposition:

Declared In

QCCompositionPickerView.h

setAllowsEmptySelection:

Sets whether to allow an empty selection in the composition picker view.

- (void) setAllowsEmptySelection:(BOOL)flag

Parameters

flag

YES to allow an empty selection. The default value is NO.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – allowsEmptySelection

Declared In

QCCompositionPickerView.h

setBackgroundColor:

Sets the background color for the composition picker view.

- (void) setBackgroundColor:(NSColor*)aColor;

Parameters

aColor

The color for the background.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – backgroundColor

Declared In

QCCompositionPickerView.h

setCompositionAspectRatio:

Sets the aspect ratio used to display compositions in the composition picker view.

- (void) setCompositionAspectRatio:(NSSize)ratio

Parameters

ratio

An aspect ratio.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – compositionAspectRatio

Declared In

QCCompositionPickerView.h

setCompositionsFromRepositoryWithProtocol:andAttributes:

Sets the compositions in the composition picker view to those that match the specified criteria.

- (void) setCompositionsFromRepositoryWithProtocol:(NSString*)protocol andAttributes:(NSDictionary*)attributes

Parameters

protocol

The protocols that you want compositions shown in the picker view to conform to. You can pass any of these protocols: QCCompositionProtocolAnimation, QCCompositionProtocolImageProducer, QCCompositionProtocolImageFilter, QCCompositionProtocolImageCompositor, QCCompositionProtocolImageTransition, and QCCompositionProtocolScreenSaverRSS.

attributes

A dictionary that contains the attributes, and their associated values, that you want compositions in the picker view to match. For example, you can pass: QCCompositionAttributeNameKey, QCCompositionAttributeDescriptionKey, QCCompositionAttributeCopyrightKey, QCCompositionAttributeBuiltInKey, and QCCompositionAttributeTimeDependentKey. Pass nil if you don’t want to filter based on the attributes.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – compositions

Declared In

QCCompositionPickerView.h

setDefaultValue:forInputKey:

Sets the default value to use for a composition input parameter.

- (void) setDefaultValue:(id)value forInputKey:(NSString*)key

Parameters

value

This default value overrides any initial value existing for composition input parameters with this key. Pass nil to clear the default value.

key

The input parameter key whose default value you want to set.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – resetDefaultInputValues

Declared In

QCCompositionPickerView.h

setDelegate:

Sets the composition picker view delegate.

- (void) setDelegate:(id)delegate

Parameters

delegate

The delegate to set.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – delegate

Declared In

QCCompositionPickerView.h

setDrawsBackground:

Sets whether the composition picker view draws its background.

- (void) setDrawsBackground:(BOOL)flag;

Parameters

flag

The background drawing state. Pass YES if the composition picker view draws its background.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – drawsBackground

Declared In

QCCompositionPickerView.h

setMaxAnimationFrameRate:

Sets the maximum frame rate for animating compositions.

- (void) setMaxAnimationFrameRate:(float)maxFPS

Parameters

maxFPS

A frame rate in frames per second. Pass 0.0 to specify no limit to the maximum value.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – maxAnimationFrameRate

Declared In

QCCompositionPickerView.h

setNumberOfColumns:

Sets the number of columns in the composition picker view.

- (void) setNumberOfColumns:(NSUInteger)columns;

Parameters

columns

The number of columns.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – numberOfColumns

Declared In

QCCompositionPickerView.h

setNumberOfRows:

Sets the number of rows in the composition picker view.

- (void) setNumberOfRows:(NSUInteger)rows;

Parameters

columns

The number of rows.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – numberOfRows

Declared In

QCCompositionPickerView.h

setSelectedComposition:

Sets a composition as selected in the composition picker view.

- (void) setSelectedComposition:(QCComposition*)composition

Parameters

composition

The composition to select. Pass nil if you don’t want to select a composition. The behavior is undefined if you pass a composition that is not in the list of compositions that are currently in the composition picker view.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – selectedComposition

Declared In

QCCompositionPickerView.h

setShowsCompositionNames:

Enables the display of composition names in the composition picker view.

- (void) setShowsCompositionNames:(BOOL)flag

Parameters

flag

YES specifies to show compositions name. The default value is NO.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

QCCompositionPickerView.h

showsCompositionNames

Retrieves whether composition names can be shown in the composition picker view.

- (BOOL) showsCompositionNames

Return Value

YES if the display of names is enabled; otherwise NO.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

QCCompositionPickerView.h

startAnimation:

Starts animating the composition in the composition picker view.

- (void) startAnimation:(id)sender

Parameters

sender

The object initiating the animation.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – stopAnimation:
• – isAnimating

Declared In

QCCompositionPickerView.h

stopAnimation:

Stops animating the composition that is currently animating in the composition picker view.

- (void) stopAnimation:(id)sender

Parameters

sender

The object stopping the animation.

Availability

• Available in Mac OS X v10.5 and later.

See Also

• – startAnimation:
• – isAnimating

Declared In

QCCompositionPickerView.h

Notifications

QCCompositionPickerViewDidSelectCompositionNotification

Posted when the user selects a composition in the picker view.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

QCCompositionPickerView.h

---