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 serves as a numerical input mechanism that allows the user to choose 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 and Pt_ARG_SLIDER_HANDLE_HEIGHT or by the size of Pt_ARG_SLIDER_IMAGE.

Mouse actions

When the user presses the mouse button, the result depends on the location 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_TICKS_ON_TOP, Pt_TICKS_ON_LEFT

Ticks are placed on the top or left of the slider, depending on the orientation.

Pt_TICKS_ON_BOTTOM, Pt_TICKS_ON_RIGHT

Ticks are placed on the bottom or right of the slider, depending on the orientation.

Pt_TICKS_TOUCH_TROUGH

Ticks touch the trough.

Pt_TICKS_ETCHED_OUT

Ticks are etched out.

Pt_TICKS_ETCHED_IN

Ticks are etched in.

Pt_SLIDER_POINT_LEFT, Pt_SLIDER_POINT_UP

The slider handle will point up or left, depending on the orientation.

Pt_SLIDER_POINT_RIGHT, Pt_SLIDER_POINT_DOWN

The slider handle will point down or right, depending on the orientation.

Pt_SLIDER_IMAGE

The slider handle will be the image specified by the Pt_ARG_SLIDER_IMAGE resource.

Pt_ARG_SLIDER_HANDLE_HEIGHT

The height of the slider handle.

Pt_ARG_SLIDER_HANDLE_WIDTH

The width of the slider handle.

Pt_ARG_SLIDER_IMAGE

The image that will be displayed as the handle if the Pt_ARG_SLIDER_FLAGS resource has the Pt_SLIDER_IMAGE flag set.

Pt_ARG_SLIDER_INCREMENT

The slider increment when the cursor keys are pressed.

Pt_ARG_SLIDER_LABEL_BR

The label string that's placed at the bottom or right of the slider, depending on the orientation.

Pt_ARG_SLIDER_LABEL_BR_COL

The color of the bottom or right label.

Pt_ARG_SLIDER_LABEL_TL

The label string that's placed at the top or left of the slider, depending on the orientation.

Pt_ARG_SLIDER_LABEL_TL_COL

The color of the top or left label.

Pt_ARG_SLIDER_MULTIPLE

The slider increment when the pointer is pressed in the trough, or Pg Up or Pg Down is pressed.

Pt_ARG_SLIDER_ORIENTATION

The location of the minimum value for the slider: on the top or bottom if the slider is vertical; on the left or right if the slider is horizontal. The possible values are:

• Pt_SLIDER_MIN_ON_TOP
• Pt_SLIDER_MIN_ON_LEFT (same as Pt_SLIDER_MIN_ON_TOP)
• Pt_SLIDER_MIN_ON_BOTTOM
• Pt_SLIDER_MIN_ON_RIGHT (same as Pt_SLIDER_MIN_ON_BOTTOM)

Pt_ARG_SLIDER_TICK_MAJOR_COL

The color of the major ticks.

Pt_ARG_SLIDER_TICK_MAJOR_DIV

The number of major divisions.

Pt_ARG_SLIDER_TICK_MAJOR_LEN

The length of the major ticks.

Pt_ARG_SLIDER_TICK_MINOR_COL

The color of the minor ticks.

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.

Pt_ARG_SLIDER_TROUGH_COL

The color of the trough.

Pt_ARG_SLIDER_TROUGH_SIZE

The height or width of the trough, depending on the orientation. The other dimension is obtained from the Pt_ARG_DIM resource, which is inherited from PtWidget.

Pt_CB_SLIDER_MOVE

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

If the widget has the Pt_CALLBACKS_ACTIVE bit set in its Pt_ARG_FLAGS resource, these callbacks are also invoked when the handle position is changed by a call to PtSetResources().

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

reason

Pt_CB_SLIDER_MOVE

reason_subtype

0 (not used).

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.