--- a/SelectionInTreeView.st	Thu Jul 31 13:49:24 1997 +0200
+++ b/SelectionInTreeView.st	Fri Aug 01 10:52:54 1997 +0200
@@ -12,8 +12,9 @@
 
 
 SelectionInListView subclass:#SelectionInTreeView
-	instanceVariableNames:'figuresWidth leftIndent figuresWidthDiv2 figuresInset showLines
-		listOfNodes dblClickEvt imageOpened imageClosed imageItem'
+	instanceVariableNames:'doubleClickSelectionBlock figuresWidth leftIndent
+		figuresWidthDiv2 figuresInset showLines listOfNodes dblClickEvt
+		imageOpened imageClosed imageItem'
 	classVariableNames:'ImageOpened ImageClosed ImageItem'
 	poolDictionaries:''
 	category:'Views-Text'
@@ -209,6 +210,26 @@
 
 !SelectionInTreeView methodsFor:'accessing-behavior'!
 
+doubleClickSelectionBlock
+    "get the conditionBlock; this block is evaluated before a doubleClick action
+     on a node containg children will be performed. In case of returning false, the
+     doubleClick will not be handled.
+   "
+   ^ doubleClickSelectionBlock
+
+
+!
+
+doubleClickSelectionBlock:aBlock
+    "set the conditionBlock; this block is evaluated before a doubleClick action
+     on a node containg children will be performed. In case of returning false, the
+     doubleClick will not be handled.
+   "
+   doubleClickSelectionBlock := aBlock
+
+
+!
+
 showLines
     "returns true if lines are shown
     "
@@ -356,39 +377,20 @@
      images again and again later"
 
     super fetchDeviceResources.
-
-    figuresInset := self class figuresInset.
-    imageOpened  := (self class imageOpened) onDevice:device.
-    imageClosed  := (self class imageClosed) onDevice:device.
-    imageItem    := (self class imageItem) onDevice:device.
+    self refetchDeviceResources
 !
 
-getFontParameters
-    "get some info of the used font and figures. They are cached since we use them
-     often ..
-    "
-    |extent|
-
-    super getFontParameters.
-
-    imageClosed isNil ifTrue:[
-        self fetchDeviceResources
-    ].
-    extent := self getMaxFiguresExtent.
-
-    extent y > fontHeight ifTrue:[
-        fontHeight := extent y
-    ].
-    figuresWidth     := extent x.
-    leftIndent       := figuresInset + figuresWidth.
-    figuresWidthDiv2 := figuresWidth // 2.
-!
-
-getMaxFiguresExtent
-    "returns maximum extent of the figures used
+fetchImageResources
+    "initialize heavily used device resources - to avoid rendering
+     images again and again later; returns maximum extent of the images used.
+     Could be redefined by subclass
     "
     |y x t|
 
+    imageOpened  := (self class imageOpened) onDevice:device.
+    imageClosed  := (self class imageClosed) onDevice:device.
+    imageItem    := (self class imageItem)   onDevice:device.
+
     y := imageClosed heightOn:self.
     x := imageClosed widthOn:self.
 
@@ -398,6 +400,7 @@
     (t := imageItem   widthOn:self)  > x ifTrue:[x := t].
 
   ^ x @ y
+
 !
 
 initialize
@@ -406,6 +409,27 @@
     super initialize.
     showLines    := true.
     dblClickEvt  := false.
+    figuresWidth     := 18.                             "/ default: will change during startup
+    figuresInset     := 2.                              "/ default: will change during startup
+    leftIndent       := figuresWidth + figuresInset.    "/ default: will change during startup
+    figuresWidthDiv2 := figuresWidth // 2.              "/ default: will change during startup
+!
+
+refetchDeviceResources
+    "reinitialize heavily used device resources - to avoid rendering
+     images again and again later
+    "
+    |extent|
+
+    figuresInset := self class figuresInset.
+    extent       := self fetchImageResources.
+
+    extent y > fontHeight ifTrue:[
+        fontHeight := extent y
+    ].
+    figuresWidth     := extent x.
+    leftIndent       := figuresInset + figuresWidth.
+    figuresWidthDiv2 := figuresWidth // 2.
 
 ! !
 
@@ -558,6 +582,11 @@
         node hasChildren ifTrue:[
          "/ node is a children container
 
+            doubleClickSelectionBlock notNil ifTrue:[
+                (doubleClickSelectionBlock value:(self selectedIndex)) ifFalse:[
+                    ^ self
+                ]
+            ].
             node numberOfChildren == 0 ifTrue:[
              "/ but without any children, thus redraw
              "/ only selected line; figure may changed
@@ -578,6 +607,7 @@
         ].
         super doubleClicked.
     ]
+
 !
 
 selectNode:aNode
@@ -614,5 +644,5 @@
 !SelectionInTreeView class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libwidg2/SelectionInTreeView.st,v 1.7 1997-07-23 07:43:16 ca Exp $'
+    ^ '$Header: /cvs/stx/stx/libwidg2/SelectionInTreeView.st,v 1.8 1997-08-01 08:52:54 ca Exp $'
 ! !