Ok, excellent! Alexandre -- _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: Alexandre Bergel http://www.bergel.eu ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;.
On Aug 11, 2014, at 4:37 AM, Peter Uhnák <i.uh...@gmail.com> wrote: > Hi Alex, > > unfortunately I've been quite busy with other stuff however it's on my todo > list so I'm planning to get back to it later this week. > I'll keep you posted. > > Peter > > > On Fri, Aug 8, 2014 at 11:57 PM, Alexandre Bergel <alexandre.ber...@me.com> > wrote: > Hi Peter, > > How things are going with having a snapOnGrid behavior? > > Cheers, > Alexandre > -- > _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: > Alexandre Bergel http://www.bergel.eu > ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. > > > > On Aug 1, 2014, at 2:36 PM, Peter Uhnák <i.uh...@gmail.com> wrote: > >> Hi Alex, >> >> While the "snap to grid" might be complicated I thought of simpler solution >> that might be achievable purely at Roassal level without the need to change >> Trachel classes. You can look at Umlet, since I am trying to copy it's grid >> behavior here. >> Basically you don't move objects with mouse immediately but only after fixed >> increments. However I've encountered a problem with TRMouseDragging>>step, >> since I would probably need to continuously sum the individual steps and >> then reset them when dragging has started. >> >> Here is a _very_ crude prototype: >> --------------------- >> "i subclassed RTDraggable and changed initializeElement: method as follows" >> initializeElement: element >> | sum gridSize | >> gridSize := 20. >> sum := 0 @ 0. >> element >> when: TRMouseDragging >> do: [ :e | >> | d t | >> t := RTGroup withAll: groupToDrag. >> (t includes: element) >> ifFalse: [ t add: element ]. >> d := element view canvas camera >> distanceFromPixelToSpace: e step. >> sum := sum + d. >> "move element only in increments of gridSize" >> d := gridSize * ((sum x / gridSize) truncated @ (sum y >> / gridSize) truncated). >> sum := sum - d. >> t translateBy: d. >> e signalUpdate ] >> --------------------- >> >> and here is a demo utilizing it >> >> ----------------------------- >> | v e1 e2 line gridSize b1 b2 b3 b4 edge | >> v := RTView new. >> >> "draw grid" >> gridSize := 20. >> >> (-20 to: 20) do: [ :i | >> b1 := RTBox element. >> b2 := RTBox element. >> b3 := RTBox element. >> b4 := RTBox element. >> b1 translateTo: (i * gridSize) @ -1000. "top side" >> b2 translateTo: (i * gridSize) @ 1000. "bottom side" >> b3 translateTo: -1000 @ (i * gridSize). "left side" >> b4 translateTo: 1000 @ (i * gridSize). "right side" >> "vertical line" >> edge := RTLine edgeFrom: b1 to: b2. >> v add: edge. >> "horizontal line" >> edge := RTLine edgeFrom: b3 to: b4. >> v add: edge. >> ]. >> >> e1 := (RTEllipse new size: 30; color: Color magenta) element. >> e1 translateTo: -20 @ 0. >> e1 @ RGGridDraggable. >> >> e2 := (RTEllipse new size: 30; color: Color magenta) element. >> e2 translateTo: 20 @ 0. >> e2 @ RGGridDraggable. >> >> (line := RTLine edgeFrom: e1 to: e2) shape color:Color black. >> >> v add: e1; add: e2; add: line. >> >> v open. >> ----------------------------- >> >> Obviously it needs a lot of fine-tuning and such. Since RTInteraction >> (RTDraggable) instances are not created directly the gridSize would have to >> be stored probably class side. Also there is a problem with resetting the >> "sum" variable when dragging starts. (There is no TRMouseDragStart event as >> far as I've seen). And also drawing the grid itself the way I've done is >> very brutal and doesn't really work if I want to move the canvas camera >> (perhaps image pattern as a background would work better). >> >> What are your thoughts on this? >> >> Peter >> >> >> >> >> On Fri, Aug 1, 2014 at 4:07 PM, Alexandre Bergel <alexandre.ber...@me.com> >> wrote: >> Hi Peter! >> >> > While playing with RTMultiLine I thought that it would be nice to have >> > option for RTDraggable elements to snap to a grid / move only by fixed >> > increments - for example the position could only be divisible by 10 (grid >> > size would be 10), so dragging from 20@10 to 26@4 would jump to 30@0. Is >> > something like this possible with current implementation? >> >> >> I first thought this would be easy. But actually it is not. >> The way to achieve the snap on grid behavior is to have an indirection in >> the Trachel classes. Each trachel shape knows its position (the position is >> contained in the matrix attached to each shape). The snap-on-grid means you >> need to slightly process the matrix coordinate. Maybe there are other way to >> do this, but it does not look like. Changing Trachel because of this seems a >> bit overkill... >> >> Cheers, >> Alexandre >> -- >> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >> Alexandre Bergel http://www.bergel.eu >> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >> >> >> >> On Jul 31, 2014, at 3:58 PM, Peter Uhnák <i.uh...@gmail.com> wrote: >> >> > While playing with RTMultiLine I thought that it would be nice to have >> > option for RTDraggable elements to snap to a grid / move only by fixed >> > increments - for example the position could only be divisible by 10 (grid >> > size would be 10), so dragging from 20@10 to 26@4 would jump to 30@0. Is >> > something like this possible with current implementation? >> > >> > The second question is: is it possible for element to subscribe for >> > position updates of another element? (I.e. element A watches for movement >> > of element B and moves accordingly). I know I could add both of them to a >> > composite shape or RTGroup (RTDraggable>>groupToDrag:), however I would >> > prefer something more loosely coupled. >> > >> > In RTDraggable>>initializeElement: i found >> > " element when: TRMouseDragging do: [ :e | e element translateBy: e >> > step. e signalUpdate ]" >> > however it is commented out so perhaps there some other way? >> > >> > Peter >> >> >> > >
