Android Tutorial [B4X] Nested layouts

Erel

Administrator
Staff member
Licensed User
1587290214570.png


Lets say that we want to build a layout such as the above where the screen is split into two halves.

If we try to build this layout with a single layout file we will quickly meet a problem.
We will add this designer script to split the screen:
B4X:
pnlTop.SetTopAndBottom(0, 50%y)
pnlBottom.SetTopAndBottom(50%y, 100%y)
The problem is that anchors are applied right before the designer script is executed, so the anchors will not be updated when the panels are resized.
This means that we will not be able to use anchors and will need to set the size of all the views in the designer script.

However there is a better solution, we can split the layout into three nice and clean layout files and load them with:
B4X:
Sub Globals
    Private WebView1 As WebView
    Private pnlTop As B4XView
    Private pnlBottom As B4XView
End Sub

Sub Activity_Create(FirstTime As Boolean)
    Activity.LoadLayout("Main")
    pnlTop.LoadLayout("Top")
    pnlBottom.LoadLayout("Bottom")
End Sub
The only designer script needed is for the two panels in the main layout.
Note that the variant size doesn't matter. The nested layouts will be resized based on the parent panels sizes.
 

Attachments

Top