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 management. The class is the descendant of Prima::IntIndents and adjusts its indents property when scrollbars are shown, hidden, or borderWidth is changed.

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

The descendant classes must follow the following guidelines:

• A class may provide "borderWidth", "hScroll", "vScroll", "autoHScroll", and "autoVScroll" property keys in profile_default() .
• A class' init() method must call the "setup_indents" method

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

• If a class needs to overload one of the "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 the border around the widget.

Depends on the "skin" property.

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

A create-only property that allows to change the scrollbar class

hScrollBarProfile, vScrollBarProfile HASH

Create-only properties that allows to adjust the scrollbar parameters when the scrollbars are created

Methods¶

setup_indents

The method is never called directly; it should be called whenever the widget layout is changed so that its indents are affected. The method is a request to recalculate indents, depending on the new 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" updates the internal widget layout, to give a chance to follow up the layout changes. Does not do anything by default.

AUTHOR¶

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

SEE ALSO¶

Prima, Prima::Lists, Prima::Edit