[EXPLAINED] ScrollAreaGadget & #PB_ScrollArea_InnerHeight
Posted: Tue Jan 30, 2024 9:07 pm
Hi there,
I'm confronted with a problem that I can't solve despite several approaches.
I'm creating an application whose purpose is to create a list of fonts in the Windows Fonts system folder or any other folder, and to display a preview of each of them in a ScrollAreaGadget. To do this, I create an image for each font with its graphic representation, which I display progressively in the ScrollAreaGadget using an ImageGadget placed just below the previous one.
My problem is that at a certain point the ordinate value used to position the ImageGadget seems to freeze, as illustrated in the image below
Of course, I've checked the type of variables used, which is Long, which is sufficient in terms of value range.
Here's a snippet of the code, immediately at the end of the processing loop, which allows me to check this:
And now, part of the result of the incremental progression and the final data value:
We can see that the final value of the variable used to determine the internal height required for total display (which will be used for #PB_ScrollArea_InnerHeight), here calculated at 63710 and 50968 with DPI scaling, is consistent.
However, after assigning this value via SetGadgetAttribute(), when I retrieve it via GetGadgetAttribute(), it doesn't match at all.
This phenomenon doesn't occur for a smaller number of ImageGadget().
However, I've done other tests where, for example, I create a ScrollAreaGadget with an internal height of 100,000 pixels, no problem, another with more than 3,000 ImageGadgets, no problem either, hence my total lack of understanding of the behaviors and results described above.
On the French forum, another method (via CanvasGadget()) was submitted to me:
The result is more or less the same:
• at the lowest scroll, not all CanvasGadgets are displayed, here 3410 instead of 4000
• AND, as in my code, the final value returned by #PB_ScrollArea_InnerHeight is " locked " at 26214! 8O
Is this a bug, a limitation, a wrong setting of some kind?
I'm confronted with a problem that I can't solve despite several approaches.
I'm creating an application whose purpose is to create a list of fonts in the Windows Fonts system folder or any other folder, and to display a preview of each of them in a ScrollAreaGadget. To do this, I create an image for each font with its graphic representation, which I display progressively in the ScrollAreaGadget using an ImageGadget placed just below the previous one.
My problem is that at a certain point the ordinate value used to position the ImageGadget seems to freeze, as illustrated in the image below
Of course, I've checked the type of variables used, which is Long, which is sufficient in terms of value range.
Here's a snippet of the code, immediately at the end of the processing loop, which allows me to check this:
Code: Select all
Debug "PositionY finale : "+DonneesGadget\PositionY
Debug "PositionY finale à l'échelle : "+Str(DonneesGadget\PositionY/FacteurEchelleY)
; Méthode 1
;SetGadgetAttribute(#GAD_FP_ZD_GALERIE,#PB_ScrollArea_InnerHeight,DonneesGadget\PositionY/FacteurEchelleY)
; Méthode 2
Protected.l ValeurX=DonneesGadget\PositionY/FacteurEchelleY
SetGadgetAttribute(#GAD_FP_ZD_GALERIE,#PB_ScrollArea_InnerHeight,ValeurX)
;
Debug "Hauteur finale innerheight : "+GetGadgetAttribute(#GAD_FP_ZD_GALERIE,#PB_ScrollArea_InnerHeight)
We can see that the final value of the variable used to determine the internal height required for total display (which will be used for #PB_ScrollArea_InnerHeight), here calculated at 63710 and 50968 with DPI scaling, is consistent.
However, after assigning this value via SetGadgetAttribute(), when I retrieve it via GetGadgetAttribute(), it doesn't match at all.
This phenomenon doesn't occur for a smaller number of ImageGadget().
However, I've done other tests where, for example, I create a ScrollAreaGadget with an internal height of 100,000 pixels, no problem, another with more than 3,000 ImageGadgets, no problem either, hence my total lack of understanding of the behaviors and results described above.
On the French forum, another method (via CanvasGadget()) was submitted to me:
Code: Select all
; Win OS - Workaround sample for removing the 32k size Limit on the ScrollAreaGadget - First testversion d19 m07 y2017
; Author Werner Albus - www.nachtoptik.de - www.quick-aes-256.de
#ImageHeight=200 ; Change you the height, you must change also the pre defined offset, it's simple
#AmountCanvas=4000
Global Dim y_pos_canvas(#AmountCanvas)
Procedure BindScrollDatas()
yy=-(#ImageHeight+10)
offset.f=0.0070042*#AmountCanvas ; Pre defined offset for max 9000 canvas, changeable
min=#AmountCanvas*(#ImageHeight+10)
If min<=GadgetHeight(0)
DisableGadget(0, 1)
Else
short_loop_1:
If y_pos_canvas(#AmountCanvas)-GetGadgetAttribute(0, #PB_ScrollArea_Y)*offset<GadgetHeight(0)-10 And min>GadgetHeight(0)
offset-0.00001
Goto short_loop_1
EndIf
For a=1 To #AmountCanvas
yy+(#ImageHeight+10)
scroll_offset.f=GetGadgetAttribute(0, #PB_ScrollArea_Y)*offset
If y_pos_canvas(a)-(#ImageHeight+10)-scroll_offset<GadgetHeight(0) And y_pos_canvas(a)-(#ImageHeight+10)-scroll_offset>-(#ImageHeight+10)
HideGadget(5+a, 0)
ResizeGadget(5+a, #PB_Ignore, yy-scroll_offset+10, #PB_Ignore, #PB_Ignore)
Else
HideGadget(5+a, 1)
EndIf
Next
DisableGadget(0, 0)
EndIf
EndProcedure
If OpenWindow(0, 0, 0, 363, 700, "ScrollAreaGadget", #PB_Window_SystemMenu | #PB_Window_ScreenCentered)
ScrollAreaGadget(0, 331, 10, 21, 680, 0, 0, 1500/#AmountCanvas+1, #PB_Container_Single)
CloseGadgetList()
ContainerGadget(#PB_Any, 10, 10, 325, GadgetHeight(0), #PB_Container_Double)
y=10
For a=1 To #AmountCanvas
CreateImage(1, Random(300, 100), #ImageHeight)
drawX=ImageWidth(1)
If StartDrawing(ImageOutput(1))
drawY=0
For x=0 To drawX Step 10
RoundBox(x, drawY, drawX-2*x, #ImageHeight-2*drawY, 20, 20, RGB(Random(255), Random(255), Random(255)))
drawY+10
Next x
DrawText(10, 10, "Image "+Str(a))
StopDrawing()
EndIf
CanvasGadget(5+a, 10+(300-drawX)/2, y, drawX, #ImageHeight) : y+#ImageHeight+10
y_pos_canvas(a)=y
SetGadgetAttribute(5+a, #PB_Canvas_Image, ImageID(1))
While WindowEvent() : Wend
Next
SetGadgetAttribute(0, #PB_ScrollArea_InnerHeight, 30759-100000/#AmountCanvas)
BindGadgetEvent(0, @BindScrollDatas())
Repeat
Select WaitWindowEvent()
Case #PB_Event_CloseWindow
End
Case #PB_Event_Gadget
Select EventGadget()
EndSelect
EndSelect
ForEver
EndIf
• at the lowest scroll, not all CanvasGadgets are displayed, here 3410 instead of 4000
• AND, as in my code, the final value returned by #PB_ScrollArea_InnerHeight is " locked " at 26214! 8O
Is this a bug, a limitation, a wrong setting of some kind?
