I was trying to apply ROTranslatingShape to produce a label sitting above the children nodes. To understand it better how to get what I need, I made ROExample>>nestingTranslate to show a permutation of the order the shapes can be applied. I have attached a screen snapshot and fileout for this. The case I am particularly interested in is el3. The 'el0' case is the reference without any ROTranslatingShape.
When running the example hover near and over the inner elements to view the misalignment of the mouse hotspot. I have marked the approximate offset in green in the snapshot.
I notice that the existing call chain goes... ROView>>localElementAt: ROElement>>elementAt: ROElement>>contains: ROElemenet>>bounds ROShape>>extentFor: (union of extent of each shape)
It seems to me the hotspot misalignment is related to the translation being applied at the shape draw level whereas the #contains: checking is done at the element level. This relies on the union of the shape extents to set the element bounds, but I can't see how that extent union could be modified to account for the translation - particular in the case of a negative translation since extents throw away information about any negative offset.
So I thought perhaps that the element #contains: checking needs might be better chained through the shaped, so that the translation could be applied similar to ROTranslatingShape>>chainedDrawOn:for: and that this would not cause any/much additional computation since all the shapes were being cycled through anyway for #extentFor:
Something like... ROView>>localElementAt: ROElement>>elementAt: ROElement>>contains: ROShape>>chainedContains:For: (for each shape)
cheers, Ben
'From Pharo1.4 of 18 April 2012 [Latest update: #14457] on 22 September 2012 at 9:41:20 pm'!
!ROExample methodsFor: 'nesting' stamp: 'BenComan 9/22/2012 17:04'! nestingTranslate " self new nestingTranslate " | rawView outer el0 el1 el2 el3 el4 el5 el6 el7 el8 | rawView := ROView new @ RODraggable.
el0 := (ROElement on: 'el0, border, label') + ROBorder + ROLabel @ RODraggable @ ROLightlyHighlightable. el0 extent: 50@50. 1 to: 4 do: [ :n | el0 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el0 elements .
el1 := (ROElement on: 'el1, border, positive translation, label') + ROBorder + (ROTranslatingShape new offset: 0 @ 20) + ROLabel @ RODraggable @ ROLightlyHighlightable. el1 extent: 50@50. 1 to: 4 do: [ :n | el1 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el1 elements .
el2 := (ROElement on: 'el2, border, label, positive translation') + ROBorder + ROLabel + (ROTranslatingShape new offset: 0 @ 20) @ RODraggable @ ROLightlyHighlightable. el2 extent: 50@50. 1 to: 4 do: [ :n | el2 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el2 elements .
el3 := (ROElement on: 'el3, border, negative translation, label') + ROBorder + (ROTranslatingShape new offset: 0 @ 20 negated) + ROLabel @ RODraggable @ ROLightlyHighlightable. el3 extent: 50@50. 1 to: 4 do: [ :n | el3 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el3 elements .
el4 := (ROElement on: 'el4, border, label, negative translation') + ROBorder + ROLabel + (ROTranslatingShape new offset: 0 @ 20 negated) @ RODraggable @ ROLightlyHighlightable. el4 extent: 50@50. 1 to: 4 do: [ :n | el4 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el4 elements .
el5 := (ROElement on: 'el5, positive translation, label, border') + (ROTranslatingShape new offset: 0 @ 20) + ROLabel + ROBorder @ RODraggable @ ROLightlyHighlightable. el5 extent: 50@50. 1 to: 4 do: [ :n | el5 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el5 elements .
el6 := (ROElement on: 'el6, label, positive translation, border,') + ROLabel + (ROTranslatingShape new offset: 0 @ 20) + ROBorder @ RODraggable @ ROLightlyHighlightable. el6 extent: 50@50. 1 to: 4 do: [ :n | el6 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el6 elements .
el7 := (ROElement on: 'el7, negative translation, label, border') + (ROTranslatingShape new offset: 0 @ 20 negated) + ROLabel + ROBorder @ RODraggable @ ROLightlyHighlightable. el7 extent: 50@50. 1 to: 4 do: [ :n | el7 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el7 elements .
el8 := (ROElement on: 'el8, label, negative translation, border') + ROLabel + (ROTranslatingShape new offset: 0 @ 20 negated) + ROBorder @ RODraggable @ ROLightlyHighlightable. el8 extent: 50@50. 1 to: 4 do: [ :n | el8 add: (ROElement spriteOn: n) @ ROLightlyHighlightable ]. ROGridLayout on: el8 elements .
outer := (ROElement spriteOn: 'outer') addAll: { el0. el1. el2. el3. el4. el5. el6. el7. el8 }. rawView add: outer. ROHorizontalLineLayout on: outer elements. rawView open ! !
