Store panel in a map

XverhelstX · Jul 28, 2012

Hello,

I'm wondering the following:
I'm having a panel which have some imageviews attached to it.
If i store the panel in a map, and call it back later, does the attached views gets lost?

When i do some logging after returning the panel, it seems that number of views = 0, but i can still keep the tag and other stuff of the panel.

Note that i'm using a class to store the panel to a map and also restore it from the same class.

Tomas

Erel · Jul 28, 2012

The views will not get lost in any case. Basic4android will try to protect you from creating a process reference to a view as it will cause a memory leak.

XverhelstX · Jul 30, 2012

I'm storing and retrieving the panels in the map as following:

B4X:

'Add a new strip
Sub btnAddStrip_Click
   'Declaration of panel to add
   Dim left, top, width, height As Int
   Dim iv As ImageView
   iv.Initialize("ivStrip")
   vw = iv
   iv.Tag = strips
   iv.Color = Colors.White
   iv.Bitmap = LoadBitmap(File.DirAssets, "tempStrip.png")
   iv.Gravity = Gravity.FILL
   strips = strips+1
   left = 10dip
   width = 240
   height = 150
   top = svStrips.Panel.NumberOfViews*(height+imgSpace) + 55dip
   
   'Add the panel to the scrollview
   svStrips.Panel.AddView(iv, left, top, width, height)
   
   'Set scrollview panel
   If svStrips.Panel.NumberOfViews >4 Then
      svStrips.Panel.height = svStrips.Panel.height + (height+imgSpace)
   End If
   
   SelectedStrip = iv.Tag

   'Saves the current canvas to a map.
   mapPanels.Put(iv.Tag, pnlCanvas)
   
   ClearPanelCanvas
End Sub

'Show the options for the strips
Sub ivStrip_Click
   vw = Sender
   ac2.show(vw)
   ClearPanelCanvas
   LoadPanelCanvas(vw.Tag)

End Sub

'Clears the canvas panel
Sub ClearPanelCanvas
   For i = pnlCanvas.NumberOfViews-1 To 0 Step -1
      pnlCanvas.RemoveViewAt(i)
   Next

End Sub

'Loads the panel belonging to the strip
Sub LoadPanelCanvas (index As Int)
   Dim pnl As Panel
   pnl = mapPanels.Get(index)
   pnlCanvas = pnl
End Sub

This keeps me loading a white panel after clicking a strip.

According to thedesolatesoul:

‹tds› i think the problem is
‹tds› that when you store the pnlCanvas in the map...it doesnt store the whole object
‹tds› just a reference to the object
‹tds› or later when you change pnlCanvas
‹tds› the reference in the map points to the same variable
‹tds› so the canvas inside the map changes too!

Is this correct, and so how would i solve this?

Tomas

Erel · Jul 30, 2012

The Panel inside the Map will not change. Your code looks a bit strange. You are not creating a new panel in btnAddStrip_Click.

XverhelstX · Jul 30, 2012

Erel said:
The Panel inside the Map will not change. Your code looks a bit strange. You are not creating a new panel in btnAddStrip_Click.

I have one big main panel (pnlCanvas) where the user is able to draw one or place an imageview on it.
I got smaller imageviews (called strips) at the right of the pnlCanvas.
When i create a new strip, or I save a strip, it will save the panel with the tag of the strip.

B4X:

'Saves the current canvas to a map.
    mapPanels.Put(iv.Tag, pnlCanvas)

When I click a strip, it will first clear the pnlCanvas and then loads the panel according to the tag of the strip.

B4X:

'Loads the panel belonging to the strip
Sub LoadPanelCanvas (index As Int)
   Dim pnl As Panel
   pnl = mapPanels.Get(index)
   pnlCanvas = pnl
End Sub

http://php.olvgroeninge.be/~sac.26A-07/B4A/IMG_20120724_205019.jpg

This is what i mean with the strips (right) and the pnlCanvas (left)
I hope i made this a little more clearer.

Tomas

Edit:

I've managed to fix it using types, but i'm resulting in a StackOverflowError.
Why does this happen? Do I have too many view? how can i resolve this?

Erel · Jul 30, 2012

StackOverflowError usually happens because you recursively call the same sub.
It can also happen if you try to log a view that has a complex reference graph that points back to itself (this is fixed in the next update).

You should check the logs and see the stack trace.

XverhelstX · Jul 30, 2012

This is the log:

** Activity (comiccreator) Resume **
java.lang.StackOverflowError
at android.text.TextLine.handleRun(TextLine.java:972)
at android.text.TextLine.measureRun(TextLine.java:416)
at android.text.TextLine.measure(TextLine.java:295)
at android.text.TextLine.metrics(TextLine.java:269)
at android.text.Layout.getLineExtent(Layout.java:942)
at android.text.Layout.draw(Layout.java:405)
at android.text.BoringLayout.draw(BoringLayout.java:400)
at android.widget.TextView.onDraw(TextView.java:5040)
at android.view.View.draw(View.java:10983)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)

at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.view.ViewGroup.drawChild(ViewGroup.java:2887)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.ViewGroup.drawChild(ViewGroup.java:2885)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.ViewGroup.drawChild(ViewGroup.java:2885)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)
at android.view.View.draw(View.java:10986)
at android.widget.FrameLayout.draw(FrameLayout.java:450)
at com.an

I don't know when it exactly happening and I cannot seem to find out how to debug it.
It happens a while after i'm adding new strips and importing new bitmaps.
I don't know in which sub it occurs or on what line.

Tomas

Erel · Jul 31, 2012

Seems like you are creating a very deeply nested layout. Is this your intention?

Maybe this example will be useful: [Class] CustomListView - A flexible list based on ScrollView

Store panel in a map

XverhelstX

Well-Known Member

Erel

B4X founder

XverhelstX

Well-Known Member

Erel

B4X founder

XverhelstX

Well-Known Member

Erel

B4X founder

XverhelstX

Well-Known Member

Erel

B4X founder