PtSlider

A widget for choosing a value from a range

Class hierarchy:

PtWidget --> PtBasic --> PtGauge --> PtSlider

For more information, see the diagram of the widget hierarchy.

PhAB icon:

Public header:

<photon/PtSlider.h>

Description:

A PtSlider widget lets you choose numerical values within a specified range from minimum to maximum.

A PtSlider widget.

A slider consists of a narrow trough (representing the total range), a movable handle, and optional tick marks. The handle -- which appears on top of the trough -- represents the current position within the range. The size of the handle is determined by Pt_ARG_SLIDER_HANDLE_WIDTH or by the size of Pt_ARG_SLIDER_IMAGE.

Mouse actions

When you press the mouse button, the result depends on the location of the pointer.

If you hold down the Ctrl key and click in the trough, the handle jumps to the position of the pointer.

Keyboard actions

where:

• The size of a "page" is determined by the Pt_ARG_SLIDER_MULTIPLE resource.
• The locations of the minimum and maximum value depend on the orientation and on the setting of the Pt_ARG_GAUGE_FLAGS resource.

New resources:

Pt_ARG_SLIDER_FLAGS

Valid flags:

Pt_SLIDER_IMAGE

The slider handle is the image specified by Pt_ARG_SLIDER_IMAGE.

Pt_ARG_SLIDER_HANDLE_COLOR

The color of the slider handle. See PgColor_t in the Photon Library Reference.

Pt_ARG_SLIDER_HANDLE_WIDTH

The width of the slider handle.

Pt_ARG_SLIDER_IMAGE

The image that's displayed as the handle if Pt_SLIDER_IMAGE is set in Pt_ARG_SLIDER_FLAGS.

Pt_ARG_SLIDER_INCREMENT

The slider increment when you press the cursor keys.

Pt_ARG_SLIDER_MULTIPLE

The slider increment when you click the pointer button in the trough, or you press Pg Up or Pg Down.

Pt_ARG_SLIDER_THICKNESS

The thickness of the slider handle, in pixels.

Pt_ARG_SLIDER_TICK_MAJOR_DIV

The number of major divisions.

Pt_ARG_SLIDER_TICK_MAJOR_LEN

The length of the major ticks, in pixels.

Pt_ARG_SLIDER_TICK_MINOR_DIV

The number of minor divisions per major division.

Pt_ARG_SLIDER_TICK_MINOR_LEN

The length of the minor ticks, in pixels.

Pt_CB_SLIDER_MOVE

A list of PtCallback_t structures that define the callbacks that the slider invokes when the handle position changes.

If you've set the Pt_CALLBACKS_ACTIVE bit set in the widget's Pt_ARG_FLAGS resource, these callbacks are also invoked when your application changes the handle position by calling PtSetResource() or PtSetResources().

Each callback is passed a PtCallbackInfo_t structure that contains at least the following members:

reason

Pt_CB_SLIDER_MOVE

reason_subtype

One of the following:

• Pt_SLIDER_INCREMENT
• Pt_SLIDER_DECREMENT
• Pt_SLIDER_MULTIPLE_INCREMENT
• Pt_SLIDER_MULTIPLE_DECREMENT
• Pt_SLIDER_DRAGGED
• Pt_SLIDER_RELEASED
• Pt_SLIDER_TO_MIN
• Pt_SLIDER_TO_MAX
• Pt_SLIDER_JUMP
• Pt_SLIDER_SET

event

A pointer to a PhEvent_t structure that describes the event that caused the callback to be invoked, or NULL if there's no event.

cbdata

A pointer to a PtSliderCallback_t structure that contains at least the following member:

int position;

A value corresponding to the slider handles location.

These callbacks should return Pt_CONTINUE.

Inherited resources:

If the widget modifies an inherited resource, the "Default override" column indicates the new value. This modification affects any subclasses of the widget.