eXept Software AG Logo

Smalltalk/X Webserver

Documentation of class 'ListModelView::Renderer':

Home

Documentation
www.exept.de
Everywhere
for:
[back]

Class: Renderer (private in ListModelView

This class is only visible from within ListModelView.

Inheritance:

   Object
   |
   +--ListModelView::Renderer
      |
      +--ListModelView::TableRenderer

Package:
stx:libwidg2
Category:
Views-Lists
Owner:
ListModelView

Description:


prepared for ListItemRenderer
.... SelectionItemRenderer ...

goal:
    allow the user to redefine the display operation and the dimesion queries


Class protocol:

instance creation
o  forView: aView


Instance protocol:

accessing-look
o  showItemInAdditionToColumns
raise an error: must be redefined in concrete subclass(es)

change & update
o  listWillChange
called before the list changed, clear caches etc.
here nothing is done

o  sizeChanged: how
Called when size of the corresponding view has changed.

o  withinUpdateFromListDo: aBlock
handle an update from the list

displaying
o  display: anItem atX: xLeft y: yTop lineHeight: h
display the item on the view

o  display: anItem atX: xLeft y: yTop lineHeight: h isHighlightedAsSelected: isHighlightedAsSelected
display the item on the view

o  postRedrawX: damageX y: yStartOrYDamage w: damageWidth from: startOrNil to: stopOrNil
called after redraw of the items in range from start to stop is done;
if no items are damaged, start and stop is set to nil.

o  validateDrawableItemsFrom: start to: stop
called before drawing items from start to stop; if the method returns false
nothing will be drawn and a invalidate is pushed on the event queue.
On default true is returned.

instance creation
o  forView: aView

o  mapped
called if the view is mapped; can be redefined by subclass

queries-dimensions
o  heightFor: anItem
returns the height of an item on the view

o  maxItemWidthOrNil
returns the maximum item width for drawing or nil
if unspecified (the default); used for cliping

o  widthFor: anItem
returns the width of an item on the view

o  widthOfWidestLineBetween: firstLine and: lastLine
returns the width of the longest line in pixels in a range; if the rendere
cannot compute the width, nil is returned (the default).



ST/X 7.2.0.0; WebServer 1.670 at bd0aa1f87cdd.unknown:8081; Wed, 10 Aug 2022 12:02:27 GMT