iOS Question problem Canvas on panel

electro179

Active Member
Licensed User
Hello

I have a list of panel
on each panel I put a canvas

This function creates a new panel with 5 labels and I init a canvas on this panel

The problem is I have the impression that he writes everything in duplicate.
I click on a panel and I want to change the color of panel to show that it is selected it does not work and if I change the value of a label I have a double display, the old value and the new one as if he wrote twice the same label in the panel

if i remove canvas.refresh not problem except that the canvas is not drawn

can3 is a global variable

B4X:
Sub AddLineList(text1 As String,text2 As String,text3 As String,text4 As String,text5 As String,deviceid As Int,output As Int)
    Dim panel As Panel

    Dim left As Int
    Dim width As Int
    Dim nbr As Int
    Dim top As Int
    Dim height As Int
    
    height = 40dip
    
    nbr =     ScrollView2.Panel.NumberOfViews
    panel.Initialize("selectline")

    
    
    top =( (nbr) * (height+3dip))+5dip
    Dim label1 As Label
    Dim label2 As Label
    Dim label3 As Label
    Dim label4 As Label
    Dim label5 As Label
    label1.Initialize("")
    label2.Initialize("")
    label3.Initialize("")
    label4.Initialize("")
    label5.Initialize("")
'    btn.Initialize("")
    label1.Text = text1
    label2.Text = text2
    label3.Text = text3
    label4.Text = text4
    label5.Text = text5
    
    label1.textColor = Colors.white
    label2.textColor = Colors.white
    label3.textColor = Colors.white
    label4.textColor = Colors.white
    label5.textColor = Colors.white
    If (Main.Istablet = True) Then
        Dim Font1 As Font = Font.CreateNew(16)
    Else
        Dim Font1 As Font = Font.CreateNew(12)
    End If
    label1.font =Font1
    label2.font =Font1
    label3.font =Font1
    label4.font =Font1
    label5.font =Font1

    label2.TextAlignment = label2.ALIGNMENT_CENTER
    label3.TextAlignment = label3.ALIGNMENT_CENTER
    label4.TextAlignment = label4.ALIGNMENT_CENTER
    label5.TextAlignment = label4.ALIGNMENT_CENTER

    
    
    Dim info(4) As Int
    info(0) = deviceid
    info(1) = output
    info(2) = nbr+1
    info(3) = text5
    
    panel.Color = Main.colorDark
    panel.Tag = info
    Dim widthscroll As Int
    widthscroll= ScrollView2.Width
    If (Main.Istablet = True) Then
        left = 5
        width = (widthscroll/7)*2.5
        panel.AddView(label1,left,3,(widthscroll/7)*2.5,height)
        
        left = left + width
        width = ((widthscroll)/7)*1
        panel.AddView(label2,left,3,width,height)
        
        left = left + width
        width = ((widthscroll)/7)*1
        panel.AddView(label3,left,3,width,height)

        left = left + width
        width = ((widthscroll)/7)*1.5   
        panel.AddView(label4,left,3,width,height)
        
        left = left + width
        width = ((widthscroll)/7)*1
        
        panel.AddView(label5,left,0dip,width,40)
    Else
        left = 3dip
        width = ((ScrollView2.Width)/7)*2.5
        panel.AddView(label1,left,0dip,((ScrollView2.Width)/7)*2.5,height)
        
        left = left + width
        width = ((ScrollView2.Width)/7)*1
        panel.AddView(label2,left,0,width,height)
        
        left = left + width
        width = ((ScrollView2.Width)/7)*1
        panel.AddView(label3,left,0,width,height)

        left = left + width
        width = ((ScrollView2.Width)/7)*1.2   
        panel.AddView(label4,left,0,width,height)
        
        left = left + width
        width = ((ScrollView2.Width)/7)*1.25
    
        panel.AddView(label5,left,0dip,width,40)
    End If
    panel.SetBorder(0,Colors.Black,7)
    
    
    
    
    ScrollView2.Panel.AddView(panel,0dip,top,ScrollView2.Width,height)
    ScrollView2.ContentHeight = ((nbr+1)*(height+3dip))+5dip
    can3.Initialize(panel)
    can3.DrawLine(title1.left + title1.Width+1-ScrollView2.left,0,title1.left + title1.Width+1-ScrollView2.left,height,Colors.RGB(0x33,0x33,0x33),1dip)
    can3.DrawLine(title2.left + title2.Width+1-ScrollView2.left,0,title2.left + title2.Width+1-ScrollView2.left,height,Colors.RGB(0x33,0x33,0x33),1dip)
    can3.DrawLine(title3.left + title3.Width+1-ScrollView2.left,0,title3.left + title3.Width+1-ScrollView2.left,height,Colors.RGB(0x33,0x33,0x33),1dip)
    can3.DrawLine(title4.left + title4.Width+1-ScrollView2.left,0,title4.left + title4.Width+1-ScrollView2.left,height,Colors.RGB(0x33,0x33,0x33),1dip)
    can3.Refresh
    

End Sub
 

Semen Matusovskiy

Well-Known Member
Licensed User
Guess, you call this Sub some times.

B4X:
 Dim panel As Panel
...
ScrollView2.Panel.AddView(panel,0dip,top,ScrollView2.Width,height)
Each time your sub creates a new panel. Meanwhile you need to remove previous instance.

Declare panel in Process_Global and add

B4X:
If panel.IsInitialized Then panel.RemoveViewFromParent
before
B4X:
panel.Initialize("selectline")
 

electro179

Active Member
Licensed User
the sub AddLineList(....,....,....) is called for each lines
It can call once or some times

the panel is declared in the sub AddLineList and so it is never initalized before

B4X:
panel.Initialize("selectline")
I have the problem even I call AddLineList() once.
 

electro179

Active Member
Licensed User
if I do
B4X:
If panel.IsInitialized Then panel.RemoveViewFromParent
The previous lines (previous panel) will be empty

I have the impression that if I initialize a canvas in a panel that already contains another element, it duplicates the elements
The layout is

ScrollView
Panel
Label1

/label1
Label2

/label2
Label3

/label3
Label4

/label4
Label5

/label5

Canvas initialized in this panel​
/Panel


Panel
Label1

/label1
Label2

/label2
Label3

/label3
Label4

/label4
Label5

/label5

Canvas initialized in this panel​
/Panel​



/scrollview
 

Semen Matusovskiy

Well-Known Member
Licensed User
Maybe I am wrong, but canvas requires a lot of memory.
Did you try to replace lines by panels / labels ?
For example, in my forms I add underline lines for textfields (like in Android) using label with height = 1 or 2 and use SetBorder to set a color.
 

emexes

Well-Known Member
Licensed User
You could also use the background color of the ScrollView.Panel, leaving a small space between the different panels.
+1 always good to have a Plan B
-1 a bit iffy, in that if the panel placement is off by a pixel, or if some pixel-position calculation rounds the wrong way, then the gap for the line of background might be occluded

I did wonder why not use the panel's border? - I assumed that the extra lines on the left and right of the panel were too much... ???
 

Erel

Administrator
Staff member
Licensed User
You should probably use xCustomListView instead of ScrollView.
 
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