B4A Library [B4X] [XUI] AS ViewPager based on xCustomListView

Hey,
thanks to @KZero for his good zPager class, i was able to extract a few things from it to make this cross platform view.

I spend a lot of time in creating views, some views i need by my self, but some views not and to create a high quality view cost a lot of time. If you want to support me, then you can do it here by Paypal or with a coffee.

This library is compatible and tested with B4A,B4I and B4J!
If you have bugs or a wish then tell me it in the comments.

Don't use autoscale in the layouts that are added to the viewpager.

On B4J use the LEFT and RIGHT keys on your keyboard to change the page.
On B4I you need the GestureRecognizer class. Download it down below.

Spoiler: Dependencies/Libraries you need for this view

B4j: jXUI,JavaObject,jPager,jReflection
B4a: XUi,Reflection,xCustomListView
B4i: iXUI,xCustomListView

Features

• cross-platform compatible
• based on a cross-platform ListView
• add and remove pages
• scroll to pages
• a good swipe feeling
• Vertical
• Carousel
• Lazy Loading
• NEW - AllowNext and AllowBack

Horizontal and Vertical

B4A Carousel and B4I Carousel

ASViewPager
Author: Alexander Stolte
Version: 2.00

Spoiler: Properties, Functions, Events, etc.

• ASViewPager
  • Events:
    • LazyLoadingAddContent (Parent As B4XView, Value As Object)
    • PageChange (Index As Int)
    • PageChanged (Index As Int)
    • PageChanged2 (NewIndex As Int, OldIndex As Int)
    • PageClick (Index As Int, Value As Object)
    • ReachEnd
    • ScrollChanged (Offset As Int)
    • TouchBegin
    • TouchEnd
  • Fields:
    • Tag As Object
  • Functions:
    • AddPage (LayoutPanel As B4XView, Value As Object) As String
    • AddPageAt (index As Int, LayoutPanel As B4XView, Value As Object) As String
      Adds an page at a special position
    • AllowBack (Allow As Boolean) As String
      If False: Prevents the user from moving to the previous page
      -The PreviousPage function will not work
      -The CurrentIndex property can be used without restrictions
    • AllowNext (Allow As Boolean) As String
      If False: Prevents the user from moving to the next page
      -The NextPage function will not work
      -The CurrentIndex property can be used without restrictions
    • Base_Resize (Width As Double, Height As Double)
    • Class_Globals As String
    • Clear As String
    • Commit As String
    • DesignerCreateView (Base As Object, Lbl As Label, Props As Map) As String
      Base type must be Object
    • getBase As B4XView
    • getCurrentIndex As Int
    • getCustomListView As b4a.example3.customlistview
    • getisScrollEnabled As Boolean
      Checks if the swipe/scroll is enabled or disabled
    • getLazyLoading As Boolean
    • getLazyLoadingExtraSize As Int
    • getLoadingPanelColor As Int
    • GetPanel (Index As Int) As B4XView
    • getSize As Int
    • GetValue (Index As Int) As Object
    • Initialize (Callback As Object, EventName As String) As String
    • IsInitialized As Boolean
      Tests whether the object has been initialized.
    • NextPage As String
    • NextPage2 As String
      Jump to next page
    • PreviousPage As String
    • PreviousPage2 As String
      jump to previous page
    • RemovePage (index As Int) As String
    • ResetLazyloadingIndex As String
    • ResetLazyLoadingPanels As String
      Removes all child views from all visible pages
      Usage:
      <code>
      xASVP_Horizontal.ResetLazyLoadingPanels
      Sleep(0)
      xASVP_Horizontal.ResetLazyloadingIndex
      xASVP_Horizontal.Commit</code>
    • Scroll2Value (Value As String) As String
      sets the current index by the value - smooth scrolls to the item
    • Scroll2Value2 (Value As String) As String
      sets the current index by the value - jumps to the item
    • setCurrentIndex (index As Int)
    • setCurrentIndex2 (index As Int)
      sets the current index - jumps to the item
    • setIgnoreLazyLoading (Ignore As Boolean) As String
      If True, the Lazy Loading event is not triggered
    • setIgnorePageChangedEvent (ignore As Boolean) As String
    • setIgnorePageChangeEvent (ignore As Boolean) As String
    • setLazyLoading (Enabled As Boolean) As String
    • setLazyLoadingExtraSize (ExtraSize As Int) As String
    • setLoadingPanelColor (Color As Int) As String
      The color of the Loading panel if Base_Resize is executed
    • setLoadingPanelHideDuration (Duration As Int) As String
    • setScroll (enabled As Boolean) As String
      B4I and B4A only
      enabled - False the scroll is deactivated
  • Properties:
    • Base As B4XView [read only]
    • CurrentIndex As Int
    • CurrentIndex2
      sets the current index - jumps to the item
    • CustomListView As b4a.example3.customlistview [read only]
    • IgnoreLazyLoading
      If True, the Lazy Loading event is not triggered
    • IgnorePageChangedEvent
    • IgnorePageChangeEvent
    • isScrollEnabled As Boolean [read only]
      Checks if the swipe/scroll is enabled or disabled
    • LazyLoading As Boolean
    • LazyLoadingExtraSize As Int
    • LoadingPanelColor As Int
      The color of the Loading panel if Base_Resize is executed
    • LoadingPanelHideDuration
    • Scroll
      B4I and B4A only
      enabled - False the scroll is deactivated
    • Size As Int [read only]

Changelog

Spoiler: Version 1.0-2.07

• 1.00
  • Release
• 1.01
  • Base_Resize is now public
  • NextPage and PreviousPage Bug Fix
  • setCurrentIndex Bug Fix
  • PageChangeEvent Bug Fix
• 1.02
  • B4I Bug Fixes
  • NextPage and PreviousPage Bug Fix
• 1.03
  • Resize BugFix
• 1.04
  • B4I Page-Height BugFix
  • B4I Page-Swipe BugFix
• 1.05
  • BugFix
• 1.06
  • Add Designer Property "Orientation" - Vertical is now supported
• 1.07
  • BugFix getCurrentIndex
  • BugFix PageChanged event is now only firing if the index is changed
  • Add setIgnorePageChangedEvent Property
  • Add TouchBegin Event
  • Add TouchEnd Event
  • BugFix PageChanged is now firing if you press on a emulator, for example the arrow up or down keys on yor keyboard
• 1.08
  • Add Tag Property
    • https://www.b4x.com/android/forum/t...om-clv-or-any-other-container.117992/#content
  • Add Clear - clears the list and sets the index to 0
  • BugFix xCustomListview Top was always 0
• 1.09
  • B4I BugFixes for Release Mode - swiping is now better
• 1.10
  • Add AddPageAt (experimental it works for my need, if you have issuses, then tell me) - Adds an page at a special position
  • Add set CurrentIndex2 - sets the current index - jumps to the item
  • Better resize handling
• 1.11
  • RemovePage Bugfixes
  • B4J ScrollPane under the hood is now Transparent
  • Add NextPage2 -Jump to next page
  • Add PrevoiusPage2 - Jump to previous page
• 1.12
  • [BETA] Add DesignerProperty Carousel - infinite swipe
    • On B4I Bounce Effect is disabled
  • B4I ScrollView Paging is now activated, this can improve the handling
• 1.13
  • Add PageClick Event
• 1.14 - read more about this update here
  • [B4I only] Add Scroll - enable or disable scroll with finger
    • ASViewPager1.Scroll(False)'disable scroll with finger
• 1.15
  • Intern Function IIF renamed to iif2
• 1.16
  • set Scroll is now B4X - disable the swipe/scroll
    • In B4J the arrow keys (Left/Right/Up/Down) are disabled if you deactivate the swipe/scroll
  • New property isScrollEnabled - checks if the swipe/scroll is enabled or disabled
  • Intern Function iif2 removed and the core iif is now used
    • B4A V11+ - B4J V9.10+ - B4I V7.50+
• 1.18
  • PageChanged Event is now firing in some cases with a delay, because of a scroll animation
  • BugFix B4A setScroll - Events from other views are now no longer blocked
• 1.19
  • BugFix on NextPage and PreviousPage
• 1.20 (read more about this update)
  • Add Event PageChange - This event is triggered immediately after the page is changed, no delay because of animations
  • Add setIgnorePageChangeEvent - prevents the PageChange event from being triggered
• 1.21
  • BugFixes
• 1.22
  • B4I Scroll = False BugFix
• 1.24
  • BugFix AddPageAt is now working better on B4A
• 1.25
  • Add Scroll2Value - sets the current index by the value - smooth scrolls to the item
    • from the AddPage and AddPageAt function the "Value" property
    • must be a string to be found
  • Add Scroll2Value2 - sets the current index by the value - jump to the item
• 1.26 (read more about this update)
  • Add Designer Property LazyLoading - activates lazy loading
    • Default: False
  • Add Designer Property LazyLoadingExtraSize - How many pages to load in advance
    • Default: 5
  • Add Event LazyLoadingAddContent - Add here your layout or views
• 1.27
  • Add get and set LazyLoadingExtraSize
• 1.28
  • Important LazyLoading improvments
• 1.29
  • Add Commit - Triggers the LazyLoadingAddContent event
    • Call this after you have filled the list
  • LazyLoading BugFixes
• 1.30
  • Add ResetLazyloadingIndex - when you call "commit" afterwards, it is guaranteed to check if there are empty panels in the lazy loading range, if so, the LazyLoading event is triggered
• 1.31
  • important resize improvments
  • Add Loading Panel if Base_Resize is calling
  • Add Designer Property LoadingPanelColor
  • Add set IgnoreLazyLoading - If True, the Lazy Loading event is not triggered
  • Add ResetLazyLoadingPanels - Removes all child views from all visible pages
  • LazyLoading Improvments
• 1.32
  • Carousel works now in Vertical mode
• 1.33
  • B4I Native paging is now used
    • The paging feels smoother now
    • In debug mode, the swiping should now also run better
• 1.34
  • B4I The GestureRecognizer is no longer needed
• 1.35 (read more)
  • Add Designer Property BackGestureGap - Only for B4I. If you use the ViewPager on a 2nd page and still want to close the page with the swipe gesture then set the checkbox to true
    • Default: False
• 2.00 (read more)
  • New dependency in B4J: jPager
  • Removed dependency in B4J: xCustomListView
  • Add GetPanel
  • Add GetValue
  • In B4J, the jPager is now used instead of the xCustomListView
    • Better performance
    • No more unwanted scrolling with the mouse
• 2.01
  • BugFixes and Improvements
  • Add Event PageChanged2
• 2.02
  • Add set LoadingPanelHideDuration - The duration of how quickly the loading panel is hidden
    • Default: 500
• 2.03
  • B4I BugFix - Prevents vertical scrolling when in horizontal mode and vice versa
• 2.04
  • B4I BugFix - The safe area is no longer observed
    • Fixes unwanted behavior when the viewpager is in the safe area
• 2.05
  • BugFix - by setting the set CurrentIndex or set CurrentIndex2, the PageChange and PageChanged event have been triggered multiple times
• 2.06
  • B4A BugFix
• 2.07
  • B4I BugFix

• 2.08
  • B4I - PageChange event is now triggered as soon as you lift your finger when changing pages, just like in B4A
  • B4J - You need jPager V1.03
  • Add AllowNext
    • Default: True
    • If False: Prevents the user from moving to the next page
      • The NextPage function will not work
      • The CurrentIndex property can be used without restrictions
  • Add AllowBack
    • Default: True
    • If False: Prevents the user from moving to the previous page
      • The PreviousPage function will not work
      • The CurrentIndex property can be used without restrictions

Have Fun

 

[Alexander Stolte]

When I do a quick swipe up (release mode, B4i) it jumps to the next tab, can it be disabled?

Attached is a beta version. Tell me if it works for you.
It should work in B4A too.

 

[angel_]

Thank you very much, it really works better than before but it still happens if the screen has a long list of elements (in this case a text list), it also happens frequently if we scroll from top to bottom but it is somewhat less problematic

 

[Alexander Stolte]

Thank you very much, it really works better than before but it still happens if the screen has a long list of elements (in this case a text list), it also happens frequently if we scroll from top to bottom but it is somewhat less problematic

strange, if the y value is greater than the x value, then it should stay on the side and not change sides. Does it stay on the side?

 

[Alexander Stolte]

I have a similar problem with a paused project where I use 2 ViewPagers, one Horizontal and the other Vertical and whenever I swipe horizontally the vertical one feels addressed too.

 

[angel_]

I have also observed (now on Android), that if you do the fast (unnatural) swipe up or down it jumps to another tab [v1.21]

 

[Alexander Stolte]

Try it now on B4A.

 

[angel_]

I have also observed (now on Android), that if you do the fast (unnatural) swipe up or down it jumps to another tab [v1.21]

This is fixed, thank you

But another problem happens, if I change the focus (by code with the event) when pressing the tab, the tab line moves to the selected tab, returns to the previous one and finally returns to the selected tab

 

[Alexander Stolte]

I had the same problem, because you set the tab in the "PageChange" event, but at the same time the TabClick event is triggered.

The solution is to change the TabMenu tab in the "PageChange" event without triggering the event.

Private Sub ASTabMenu1_TabClick(index As Int)
    ASViewPager1.CurrentIndex = index
End Sub

Private Sub ASViewPager1_PageChange(Index As Int)
    ASTabMenu_horizontal.SetTab(Index,False,False) 'with event = false
End Sub

 

[angel_]

Private Sub ASTabMenu1_TabClick(index As Int)
    ASViewPager1.CurrentIndex = index
End Sub

Private Sub ASViewPager1_PageChange(Index As Int)
    ASTabMenu_horizontal.SetTab(Index,False,False) 'with event = false
End Sub

I have tried this solution but the same thing happens

 

[Hamedshafiee]

hi all
its possible add CustomListView in page !?
i have some error like this

code

    Dim tmp_xpnl As B4XView = xui.CreatePanel("")
    tmp_xpnl.LoadLayout("xclv")
    tmp_xpnl.SetLayoutAnimated(0,0,0,ASViewPager1.Base.Width,ASViewPager1.Base.Height)
    tmp_xpnl.BringToFront
    ASViewPager1.AddPage(tmp_xpnl,"")

    xclvitem.AddTextItem("1Aaaa" & CRLF & "Bbbb", "b")

Spoiler: Error

*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
Panel size is unknown. Layout may not be loaded correctly.
Error occurred on line: 34 (B4XMainPage)
java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.keywords.Common.CallSubDebug2(Common.java:1055)
at com.as.viewpager.b4xpagesmanager._createpageifneeded(b4xpagesmanager.java:1060)
at com.as.viewpager.b4xpagesmanager._showpage(b4xpagesmanager.java:417)
at com.as.viewpager.b4xpagesmanager._addpage(b4xpagesmanager.java:245)
at com.as.viewpager.b4xpagesmanager._addpageandcreate(b4xpagesmanager.java:259)
at com.as.viewpager.b4xpagesmanager._initialize(b4xpagesmanager.java:165)
at com.as.viewpager.main._activity_create(main.java:408)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:732)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:351)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:255)
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
at com.as.viewpager.main.afterFirstLayout(main.java:105)
at com.as.viewpager.main.access$000(main.java:17)
at com.as.viewpager.main$WaitForLayout.run(main.java:83)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6816)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1563)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1451)
Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at anywheresoftware.b4a.debug.Debug.CallSub4(Debug.java:336)
at anywheresoftware.b4a.debug.Debug.CallSubNew2(Debug.java:285)
... 24 more
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at anywheresoftware.b4a.debug.Debug.CallSub4(Debug.java:318)
... 25 more
Caused by: java.lang.IllegalArgumentException: Layout: -20 < 0
at android.text.Layout.<init>(Layout.java:187)
at android.text.StaticLayout.<init>(StaticLayout.java:478)
at android.text.StaticLayout.<init>(StaticLayout.java:464)
at android.text.StaticLayout.<init>(StaticLayout.java:442)
at android.text.StaticLayout.<init>(StaticLayout.java:422)
at anywheresoftware.b4a.objects.StringUtils.MeasureMultilineTextHeight(StringUtils.java:50)
at b4a.example3.customlistview._createlabel(customlistview.java:230)
at b4a.example3.customlistview._insertattextitem(customlistview.java:702)
at b4a.example3.customlistview._addtextitem(customlistview.java:78)
at com.as.viewpager.b4xmainpage._b4xpage_created(b4xmainpage.java:105)
... 27 more
** Activity (main) Resume **

 

[Alexander Stolte]

You need to add first the width/height and then load the layout:

Dim tmp_xpnl As B4XView = xui.CreatePanel("")
tmp_xpnl.SetLayoutAnimated(0,0,0,ASViewPager1.Base.Width,ASViewPager1.Base.Height)
tmp_xpnl.LoadLayout("xclv")

 

[Alexander Stolte]

Update

• 1.24
  • BugFix AddPageAt is now working better on B4A

 

[angel_]

Any improvement about this?

But another problem happens, if I change the focus (by code with the event) when pressing the tab, the tab line moves to the selected tab, returns to the previous one and finally returns to the selected tab

 

[Alexander Stolte]

Any improvement about this?

Make a test project with the issue.

 

[Alessandro71]

I'm using ASViewPager in a B4J project
I'm probably not handling resize correctly, because when I resize the window containing the ASViewPager, all other views resize correctly, but the content of the ViewPager itself is unaffected
What am I missing?

 

[Alexander Stolte]

What am I missing?

Make a new thread and make a example project what the issue shows, thanks.

 

[Alessandro71]

Make a new thread and make a example project what the issue shows, thanks.

here it is: the sample is based on your own example

ASViewPager resize problem

I'm using ASViewPager in a B4J project It looks like the resize handling is not working correctly Here is a sample project: the pager contains a single label with bottom-right anchor Try resizing the window by increasing its width, and the label won't follow the right border

www.b4x.com

thank you

 

[Lello1964]

How can add .bal page using .addpage() ?

 

[Alexander Stolte]

How can add .bal page using .addpage() ?

Dim tmp_xpnl As B4XView = xui.CreatePanel("")
tmp_xpnl.SetLayoutAnimated(0,0,0,ASViewPager1.Base.Width,ASViewPager1.Base.Height)
tmp_xpnl.LoadLayout("xclv")
ViewPager.AddPage(tmp_xpnl,"")

 

[Lello1964]

Hi Alex,

there is a Property to scroll to page without effects ?, to move from a page to another without effects,