Scrollbar

  + Object
    + Display
      + UIComponent
        + Control
          + AdjustableControl
            + Scrollbar

The Scrollbar class implements the behaviours specific to scrollbars. This control is used to represent a value between two given boundaries to scroll parts of another control. This class is not instantiable, derivable or cloneable. The only instances available to the programmer are those automatically generated by HB++ when you place a control on a form.

When the value of the Height property is greater than the value of the Width property, the scrollbar is displayed vertically otherwise it is displayed horizontally. Note that horizontal scrollbars are supported beginning with Palm OS^® version 3.5.

It is possible to attach a scrollbar to a multiline Field control or a Grid control. In this case, the interaction between the scrollbar and the control are automatically managed by the system and there is no additional code to write. On the other hand, if the scrollbar is not attached to a control, you must programatically define its mimimum and maximum values, and handle raised events.

This class offers no methods to the programmer. All the necessary functionality for managing a scrollbar is inherited by the AdjustableControl class. Refer to the documentation of this object for more information.

Inherited from AdjustableControl	Description

LargeChange	Value added or substracted to the Value property when the user clicks the area between the scroll box and one of the scroll arrows.
Max	Maximum value for the control.
Min	Minimum value for the control.
Scroll	Raised when the user releases the cursor of the scrollbar or slider.
SetValues	Sets the value of all the control properties.
Track	Raised when the user moves the cursor of the scrollbar or slider.
Value	Current control value.

Inherited from Control	Description

DrawFocusRing	Draws the focus ring.
GotFocus	Event raised when the control gains the focus.
Layer	Layer to which the control belongs.
LostFocus	Event raised when the control loses the focus.
NavFlags	Navigation flags for the control.
RemoveFocusRing	Erase the focus ring.
Tag	String associated with the control.
Visible	Indicates if a control is visible or not.

Inherited from UIComponent	Description

ComponentToScreen	Converts coordinates relative to a component into coordinates relative to the screen.
FiveWayNavigator	Event raised when the user presses one of the 5-way navigator keys.
Height	Element height.
Left	Distance between the left edge of the form and the left edge of the element.
Move	Moves or resizes an element.
PenDown	Event raised when the user touches an UI element with the stylus.
PenMove	Event raised when the user moves the stylus.
PenUp	Event raised when the user releases the stylus.
ScreenToComponent	Converts coordinates relative to the screen into coordinates relative a component.
Top	Distance between the top edge of the form and the top edge of the element.
UIRef	Internal reference to a control.
Width	Element width.

Inherited from Display	Description

Arc	Draws an arc.
BackColor	Background color.
BatchLimit	Size of the graphics instruction buffer.
CoordinateSystem	Coordinates system.
CopyArea	Efficiently copies part of a Display object to another.
DrawFont	Font used to draw the text.
Flush	Empties the graphics instruction buffer.
FontMetrics	Returns a FontMetrics object describing the physical charateristics of the currently active font.
ForeColor	Foreground color.
GetPixel	Queries the color of a given pixel.
hWin	Returns the window handle.
Line	Draws a line.
Oval	Draws a circle or ellipse.
Pattern	Defines the pattern used to fill drawings.
Polygon	Draws a polygon.
PutPixel	Sets the color of a pixel.
Rectangle	Draw a rectangle.
ResID	Identifier of the resource associated with the object.
ScaleFont	Enable or disable font scaling.
TextColor	Text color.
TextOut	Draw text.

Inherited from Object	Description

ClassID	Returns the type identifier corresponding to the actual class of the object.
Implements	Determines whether the object implements the features of a given class.
Iterate	Event raised to iterate over the elements of a container object.
Recipient	Recipient of events sent by the object.
Serialize	Event raised to serialize the object content into a stream.

System	Minimal version	Remarks

Palm OS	Palm OS 3.0	N/A