It is because of another call to measure(), but that's not getting lucky, it's being scheduled when you change includeInLayout.
-Josh On Mon, Jun 9, 2008 at 10:39 AM, Richard Rodseth <[EMAIL PROTECTED]> wrote: > I'm still somewhat confused, but have hacked up a workable solution as > follows: > > > <mx:Canvas id="scrollableArea" width="100%" height="100%" > verticalScrollPolicy="auto" > horizontalScrollPolicy="auto"> > > <mx:Canvas id="podSurface" width="100%" height="100%" > verticalScrollPolicy="off" horizontalScrollPolicy="off" minWidth="950" > minHeight="600"> > <view:TiledCanvas2 id="tiledView" width="100%" height="100%" /> > </mx:Canvas> > </mx:Canvas> > > podSurface.minWidth and minHeight get changed dynamically when a pod > is expanded, and the scrollbars and scroll extent adjust > appropriately. > > Here's the interesting thing. TiledCanvas2 still uses the inherited > Canvas.measure(), but the updateDisplayList implementation now sets > includeInLayout to false for the hidden pods, in addition to setting > x,y,width,height and visible. Am I just getting lucky because of some > call to measure() that occurs after updateDisplayList() is called? > Also, maybe if I was calling setActualSize in UDL, my solution would > no longer work... > > The thing I have a hard time understanding is that the docs talk about > measure() as setting the "intrinsic" or "natural" size of the > component, but in a case like this, what is that? What concept tells > me that an appropriate implementation of measure would "estimate" the > tiling as Alex suggests but use measured sizes of children, when the > layout itself is determined by the component size, not vice versa. > > I should step through Canvas.measure and see what numbers it's coming > up with that affect what happens all way up the hierarchy, even > though the component's size is independent of the contents of each > pod. My head hurts. > > > On Sat, Jun 7, 2008 at 11:36 PM, Richard Rodseth <[EMAIL > PROTECTED]<rrodseth%40gmail.com>> > wrote: > > Thanks, Alex. That gives me a lot to mull over. > > Since the only use case of interest that doesn't work is the one where > > you'd like to specify a minimum size for the tiled view, it's an awful > > lot of extra work, but I'll think it over. > > If I can crack my other long-standing challenge (the ScaleOrCenterView > > of another thread), then I could probably get by with no scroll bars > > at all. > > > > Thanks again for the solution outline. > > > > On Sat, Jun 7, 2008 at 11:17 PM, Alex Harui <[EMAIL > > PROTECTED]<aharui%40adobe.com>> > wrote: > >> Canvas's measure() probably expects all children to be visible or > excluded > >> via includeInLayout. Since I don't think that's what you want, you'll > need > >> to write your own measure method(). > >> > >> > >> > >> The measure() method should assume that all children are property > addChild'd > >> (and thus your charts shouldn't be unparented) and use the measured > sizes of > >> its children to calculate its measuredWidth/Height. It would probably > just > >> call getExplcitOrMeasuredWidth/Height on the children if > selectedChild==null > >> and estimate what the tile layout will look like, or if there is a > >> selectedChild, just measure that one child. > >> > >> > >> > >> Based on those measurements and any other constraints on your component, > its > >> parent will determine its size and your component's updateDisplayList > gets > >> called with that size. In your override of updateDL, you would see if > >> selectedChild==null and do the final sizing and positioning of the > children > >> and probably make all children visible, or if selectedChild is set, make > all > >> other children invisible and size and position that one child to fill > the > >> unscaledWidth/Height passed into updateDL. > >> > >> > >> > >> I would not remove and re-add children when selectedChild changes. It > would > >> likely cause more measuring and layout again. > >> > >> > >> > >> -Alex > >> > >> > >> > >> ________________________________ > >> > >> From: [email protected] <flexcoders%40yahoogroups.com>[mailto: > [email protected] <flexcoders%40yahoogroups.com>] On > >> Behalf Of Richard Rodseth > >> Sent: Saturday, June 07, 2008 1:30 PM > >> To: [email protected] <flexcoders%40yahoogroups.com> > >> Subject: Re: [flexcoders] Measurement and scrolling > >> > >> > >> > >> Thanks for indulging me, everyone. I wish I could share all the code > >> now - I certainly hope to later. I'm sorry to say I find that ESRIA > >> example quite inscrutable as sample code, though the UI is certainly > >> nice. > >> > >> So, to review where I am, I have a component that tiles its children > >> and resizes rather well (perhaps by accident). It derives from Canvas > >> (should possibly be UIComponent), and the updateDisplayList method > >> sets the x,y,width,height of the children (should possibly be calling > >> setActualSize, thought it currently doesn't assume that the children > >> are UIComponents, even though they are). The measure() method is > >> inherited from Canvas. > >> > >> When an individual pod is maximized, the contents of the display list > >> is not changed. Rather updateDisplayList sets the visible property as > >> well. That's something I'm trying to rectify now, so that measure() > >> will be correct, but I'm running into some problems (eg. charting > >> classes expecting a parent). Any suggestions regarding this aspect? > >> I'm trying something like the following. > >> > >> public function set selectedChild(child:DisplayObject) : void { > >> trace("selectedChild"); > >> _selectedChild = child; > >> if (child == null) { > >> this.removeAllChildren(); > >> for each (var child:DisplayObject in _savedTiles) { > >> this.addChild(child); > >> } > >> _savedTiles = null; > >> } else { > >> _savedTiles = this.getChildren(); > >> this.removeAllChildren(); > >> this.addChild(_selectedChild); > >> } > >> invalidateSize(); > >> } > >> > >> I thought of using visible/includinLayout, but then I'd have to > >> introduce the child-is-UIComponent assumption (which I realize may > >> ultimately be necessary). > >> > >> On Sat, Jun 7, 2008 at 9:35 AM, Daniel Gold <[EMAIL > >> PROTECTED]<danielggold%40gmail.com>> > wrote: > >>> You may want to look at the code in PodLayoutManager.as from the Flex > >>> Dashboard example as it seems to be very similar to what you're doing > >>> > >>> http://examples.adobe.com/flex3/devnet/dashboard/main.html > >>> > >>> > >>> On Fri, Jun 6, 2008 at 12:04 AM, Josh McDonald <[EMAIL > >>> PROTECTED]<dznuts%40gmail.com>> > wrote: > >>>> > >>>> Measure can always be bigger than the actual width/height, that's what > >>>> it's for. > >>>> > >>>> On Fri, Jun 6, 2008 at 11:32 AM, Richard Rodseth <[EMAIL > >>>> PROTECTED]<rrodseth%40gmail.com> > > > >>>> wrote: > >>>>> > >>>>> No, I mean like zooming a window. I think the problem lies in how I > >>>>> tell the TiledCanvas that one of its children is the zoomed one > >>>>> (setting "visible" of all the others to false in updateDisplayList). > >>>>> Stay tuned. > >>>>> > >>>>> However, setting that aside, it also seems as though I might be > >>>>> commiting a hack if I allow the measured size of the TiledCanvas to > >>>>> remain larger than its bounds, even though it allows the scrolling to > >>>>> work (at least in the all-tiles-shown case). > >>>>> > >>>>> On Thu, Jun 5, 2008 at 5:46 PM, Josh McDonald <[EMAIL > >>>>> PROTECTED]<dznuts%40gmail.com>> > wrote: > >>>>> > I'm not sure exactly what you're doing, or what you're trying to > >>>>> > achieve > >>>>> > yet. By "expanding a tile" do you mean you're setting the minimum > to > >>>>> > be > >>>>> > bigger, or you're manually overriding the decisions the base > Container > >>>>> > implementation makes in updateDisplayList()? > >>>>> > > >>>>> > On Fri, Jun 6, 2008 at 10:41 AM, Richard Rodseth < > [EMAIL PROTECTED] <rrodseth%40gmail.com>> > >>>>> > wrote: > >>>>> >> > >>>>> >> The docs say: > >>>>> >> > >>>>> >> If the horizontalScrollPolicy is ScrollPolicy.AUTO, the horizontal > >>>>> >> scroll bar appears when all of the following are true: > >>>>> >> > >>>>> >> * One of the container's children extends beyond the left edge or > >>>>> >> right edge of the container. > >>>>> >> * The clipContent property is true. > >>>>> >> * The width and height of the container are large enough to > >>>>> >> reasonably accommodate a scroll bar. > >>>>> >> > >>>>> >> And sure enough, if I set a static minimum on tiledView, I get the > >>>>> >> desired effect. > >>>>> >> > >>>>> >> If I expand a tile and change the minimum to something else, any > idea > >>>>> >> which invalidate method(s) I should call? > >>>>> >> > >>>>> >> On Thu, Jun 5, 2008 at 4:57 PM, Josh McDonald <[EMAIL > >>>>> >> PROTECTED]<dznuts%40gmail.com> > > > >>>>> >> wrote: > >>>>> >> > If you want to be able to measure your subcomponents, always use > >>>>> >> > setActualSize. I learned that the hard way recently :) > >>>>> >> > > >>>>> >> > I've recently been doing a whole bunch of measure and > >>>>> >> > updatedisplaylist > >>>>> >> > voodoo for a custom container, so I'll be slightly helpful! > >>>>> >> > > >>>>> >> > -Josh > >>>>> >> > > >>>>> >> > On Fri, Jun 6, 2008 at 9:36 AM, Richard Rodseth > >>>>> >> > <[EMAIL PROTECTED] <rrodseth%40gmail.com>> > >>>>> >> > wrote: > >>>>> >> >> > >>>>> >> >> Clearly I haven't mastered layout and measurement. > >>>>> >> >> > >>>>> >> >> I've implemented a custom component which tiles its children in > >>>>> >> >> equal-sized tiles, but also has a state (not a flex state) > where > >>>>> >> >> one > >>>>> >> >> tile fills the component. > >>>>> >> >> > >>>>> >> >> I subclassed Canvas and set the sizes and positions of children > in > >>>>> >> >> updateDisplayList. I didn't override measure(), but it works > very > >>>>> >> >> nicely, resizing children smoothly as it is resized. > >>>>> >> >> > >>>>> >> >> Now, however, I would like to set a minimum width and height > for > >>>>> >> >> the > >>>>> >> >> tiled view, after which scroll bars appear. The minimum will be > >>>>> >> >> different if the component is in the one-tile-expanded case. > >>>>> >> >> > >>>>> >> >> Can I do this without further mods to my component? > >>>>> >> >> Should my updateDisplayList be calling setActualSize rather > than > >>>>> >> >> setting x,y,width, height? > >>>>> >> >> Should I have a measure() implementation? > >>>>> >> >> How would it differ from the inherited one? > >>>>> >> >> In a scenario like the following, would I set the minWidth and > >>>>> >> >> minHeight on the parent or child? > >>>>> >> >> Or, to ask another way, do the the scrollpolicy and minimum > >>>>> >> >> properties > >>>>> >> >> always belong on the same component? > >>>>> >> >> > >>>>> >> >> <mx:Canvas id="scrollableArea" width="100%" height="100%" > >>>>> >> >> verticalScrollPolicy="auto" > >>>>> >> >> horizontalScrollPolicy="auto"> > >>>>> >> >> > >>>>> >> >> <view:TiledCanvas id="tiledView" > >>>>> >> >> width="100%" height="100%" > >>>>> >> >> > > >>>>> >> >> </view:TiledCanvas> > >>>>> >> >> </mx:Canvas> > >>>>> >> >> > >>>>> >> >> Thanks. > >>>>> >> > > >>>>> >> > > >>>>> >> > > >>>>> >> > -- > >>>>> >> > "Therefore, send not to know For whom the bell tolls. It tolls > for > >>>>> >> > thee." > >>>>> >> > > >>>>> >> > :: Josh 'G-Funk' McDonald > >>>>> >> > :: 0437 221 380 :: [EMAIL PROTECTED] <josh%40gfunk007.com> > >>>>> >> > > >>>>> > > >>>>> > > >>>>> > > >>>>> > -- > >>>>> > "Therefore, send not to know For whom the bell tolls. It tolls for > >>>>> > thee." > >>>>> > > >>>>> > :: Josh 'G-Funk' McDonald > >>>>> > :: 0437 221 380 :: [EMAIL PROTECTED] <josh%40gfunk007.com> > >>>>> > > >>>> > >>>> > >>>> > >>>> -- > >>>> "Therefore, send not to know For whom the bell tolls. It tolls for > thee." > >>>> > >>>> :: Josh 'G-Funk' McDonald > >>>> :: 0437 221 380 :: [EMAIL PROTECTED] <josh%40gfunk007.com> > >>> > >>> > >> > >> > > > > -- "Therefore, send not to know For whom the bell tolls. It tolls for thee." :: Josh 'G-Funk' McDonald :: 0437 221 380 :: [EMAIL PROTECTED]
