NAME

Prima::Widget::GroupScroller - optional automatic scroll bars

DESCRIPTION

The class is used for widgets that contain optional scroll bars, and provides means for their maintenance. The class is the descendant of Prima::IntIndents, and adjusts the indents property when scrollbars are shown or hidden, or borderWidth is changed.

The class does not provide range selection for the scrollbars; the descentant classes must implement that.

The descendant classes must follow the guidelines:

• A class must provide borderWidth, hScroll, and vScroll property keys in profile_default() . A class may provide autoHScroll and autoVScroll property keys in profile_default() .

• A class' init() method must set {borderWidth}, {hScroll}, and {vScroll} variables to 0 before the initialization, call setup_indents method, and then assign the properties from the object profile.

  If a class provides autoHScroll and autoVScroll properties, these must be set to 0 before the initialization.

• If a class needs to overload one of borderWidth, hScroll, vScroll, autoHScroll, and autoVScroll properties, it is mandatory to call the inherited properties.

• A class must implement the scroll bar notification callbacks: HScroll_Change and VScroll_Change.

• A class must not use the reserved variable names, which are:

          {borderWidth}  - internal borderWidth storage
          {hScroll}      - internal hScroll value storage
          {vScroll}      - internal vScroll value storage
          {hScrollBar}   - pointer to the horizontal scroll bar
          {vScrollBar}   - pointer to the vertical scroll bar
          {bone}         - rectangular widget between the scrollbars
          {autoHScroll}  - internal autoHScroll value storage
          {autoVScroll}  - internal autoVScroll value storage

  The reserved method names:

          set_h_scroll
          set_v_scroll
          insert_bone
          setup_indents
          reset_indents
          borderWidth
          autoHScroll
          autoVScroll
          hScroll
          vScroll

  The reserved widget names:

          HScroll
          VScroll
          Bone

Properties

autoHScroll BOOLEAN

Selects if the horizontal scrollbar is to be shown and hidden dynamically, depending on the widget layout.

autoVScroll BOOLEAN

Selects if the vertical scrollbar is to be shown and hidden dynamically, depending on the widget layout.

borderWidth INTEGER

Width of 3d-shade border around the widget.

Recommended default value: 2

hScroll BOOLEAN

Selects if the horizontal scrollbar is visible. If it is, {hScrollBar} points to it.

vScroll BOOLEAN

Selects if the vertical scrollbar is visible. If it is, {vScrollBar} points to it.

scrollBarClass STRING = Prima::ScrollBar

Create-only property that allows to change scrollbar class

hScrollBarProfile, vScrollBarProfile HASH

Create-only property that allows to change scrollbar parameters when it is being created

Methods

setup_indents

The method is never called directly; it should be called whenever widget layout is changed so that indents are affected. The method is a request to recalculate indents, depending on the widget layout.

The method is not reentrant; to receive this callback and update the widget layout, that in turn can result in more setup_indents calls, overload reset_indents .

reset_indents

Called after setup_indents is called and internal widget layout is updated, to give a chance to follow-up the layout changes.

AUTHOR

Dmitry Karasik, <dmitry@karasik.eu.org>.

SEE ALSO

Prima, Prima::Lists, Prima::Edit