Android Tutorial ActionBar / Sliding Pages tutorial

Roger C said:

Netchicken,

I've made a solution with one Activity and classes loading Layouts and this works fine for me so far. Supplied here are the framework of this setup. I've been searching a lot for a working solution and thought I'd share this, might help others in the same situation.

The Activity has an Actionbar in top and another in bottom (which works as a statusbar for me).
Changes in the Actionbars can be done by calling a sub in Main like:

B4X:

CallSub(Main,"ActivityLowerBar")

or in the top bar

B4X:

CallSub(Main,"ActivityTopBar")

I use KeyValueStore to send variables between classes and activity, a bit slower than global variables but safer if the app shuts down.

I also have slidingmenues (http://www.b4x.com/android/forum/threads/jfeinstein10-slidingmenu-library.36482/) to the left, with buttons for selecting function and to the right with a ScrollView that can be used for anything you want.

The menubuttons loads the classes like this:

B4X:

sm.HideMenus
Activity.RemoveAllViews
lClsHistory.Initialize(Me, Activity, 2)

Then the class loads the Layouts and each class will handle the events from that layout.
This means you have the Activity common for the project and just change the visible layouts by initializing the classes.

I've also implemented a Multilanguage function based on this http://www.b4x.com/android/forum/threads/ahlocale-library.7561/.
Texts are used in this way:

B4X:

btnKund.text=trans.GetText("Customer")

I only have Swedish at the moment as complement to English (the english is the text Customer above) and the Swedish is looked up in a text file in the folder /Files.

Noticed that the Backbutton on the device don't work but thats easy to solve for you...
The sliding doesn't work so good on the emulator but it does on a real device.

Notice that you will need some libraries...
Since this frame is taken from my complete app there are a lot of libs and I really don't know which are used for only the frame to work... But try and add them one at a time when you get error...
These are the libs used: AHLocale, Core, DateUtils, Dialogs, HTTP, JavaObject, JSON, Net, Phone, RandomAccessFile, Reflection, ScrollView2D, SlidingMenuWrapper, SQL, StdActionbar, StringFunctions, StringUtils, TabHostExtras, XmlSax.

Click to expand...

Erel said:

A simpler and better looking solution is now available: https://www.b4x.com/android/forum/threads/tabstripviewpager-better-viewpager.63975/

StdActionBar library allows you to create layouts that use the action bar as a navigation interface.
Note that StdActionBar requires Android 4+.

In this tutorial we will create this layout:

View attachment 22073 View attachment 22074

The user can switch pages with a swipe gesture.

StdViewPager holds several panels and supports the swipe gesture.

Using StdViewPager is quite simple:

1. Initialize it and set the number of pages and their size.
2. Add it to its parent.
3. Create the internal pages layouts.

B4X:

Dim height As Int = CalculateHeight(True, True)
vp.Initialize("vp", 3, 100%x, height) 'vp is a StdViewPager object
Activity.AddView(vp.AsView, 0, 0, 100%x, height)
'load the pages layouts
vp.Panels(0).LoadLayout("0")
vp.Panels(1).LoadLayout("1")
vp.Panels(2).LoadLayout("2")

The next step is to add the ActionBar tabs:

B4X:

bar.Initialize("bar")
bar.NavigationMode = bar.NAVIGATION_MODE_TABS
bar.AddTab("Tab 1")
bar.AddTab("Tab 2")
bar.AddTab("Tab 3")

We need to synchronize the selected tab and the selected page:

B4X:

Sub VP_PageSelected (Position As Int)
   If bar.SelectedIndex <> Position Then bar.SelectedIndex = Position
End Sub

Sub bar_TabChanged(Index As Int, STab As StdTab)
   If vp.currentPage <> Index Then vp.ScrollTo(Index, False)
End Sub

CalculateHeight (TabsMode As Boolean, SplitEnabled As Boolean) is a helper sub that calculates the pages height based on the two features.
As you can see in the first screenshot, the split mode is enabled in this case. In split mode the action bar menu items appear at the bottom in portrait mode (phones only). This is set by adding the following line to the manifest editor:

B4X:

SetApplicationAttribute(android:uiOptions, "splitActionBarWhenNarrow")

The project is attached. Note that it requires StdActionBar v1.50+.

Tips:

- You can show the "up indicator" by setting ShowUpIndicator to True:

You can then handle the ButtonClicked event and use it to navigate to the "parent" activity.

- The holo.light theme is used in this project. It is done with this manifest line:

B4X:

SetApplicationAttribute(android:theme, "@android:style/Theme.Holo.Light")

Click to expand...

Erel said:

I recommend you to switch to TabStripViewPager. I tested it in release mode. The layout appears very quickly. There is a very short moment where you see an empty activity.

Click to expand...

Erel said:

A simpler and better looking solution is now available: https://www.b4x.com/android/forum/threads/tabstripviewpager-better-viewpager.63975/

StdActionBar library allows you to create layouts that use the action bar as a navigation interface.
Note that StdActionBar requires Android 4+.

In this tutorial we will create this layout:

View attachment 22073 View attachment 22074

The user can switch pages with a swipe gesture.

StdViewPager holds several panels and supports the swipe gesture.

Using StdViewPager is quite simple:

1. Initialize it and set the number of pages and their size.
2. Add it to its parent.
3. Create the internal pages layouts.

B4X:

Dim height As Int = CalculateHeight(True, True)
vp.Initialize("vp", 3, 100%x, height) 'vp is a StdViewPager object
Activity.AddView(vp.AsView, 0, 0, 100%x, height)
'load the pages layouts
vp.Panels(0).LoadLayout("0")
vp.Panels(1).LoadLayout("1")
vp.Panels(2).LoadLayout("2")

The next step is to add the ActionBar tabs:

B4X:

bar.Initialize("bar")
bar.NavigationMode = bar.NAVIGATION_MODE_TABS
bar.AddTab("Tab 1")
bar.AddTab("Tab 2")
bar.AddTab("Tab 3")

We need to synchronize the selected tab and the selected page:

B4X:

Sub VP_PageSelected (Position As Int)
   If bar.SelectedIndex <> Position Then bar.SelectedIndex = Position
End Sub

Sub bar_TabChanged(Index As Int, STab As StdTab)
   If vp.currentPage <> Index Then vp.ScrollTo(Index, False)
End Sub

CalculateHeight (TabsMode As Boolean, SplitEnabled As Boolean) is a helper sub that calculates the pages height based on the two features.
As you can see in the first screenshot, the split mode is enabled in this case. In split mode the action bar menu items appear at the bottom in portrait mode (phones only). This is set by adding the following line to the manifest editor:

B4X:

SetApplicationAttribute(android:uiOptions, "splitActionBarWhenNarrow")

The project is attached. Note that it requires StdActionBar v1.50+.

Tips:

- You can show the "up indicator" by setting ShowUpIndicator to True:

You can then handle the ButtonClicked event and use it to navigate to the "parent" activity.

- The holo.light theme is used in this project. It is done with this manifest line:

B4X:

SetApplicationAttribute(android:theme, "@android:style/Theme.Holo.Light")

Click to expand...

    'load the pages layouts
    vp.Panels(0).LoadLayout("ProizvodiTop")
    vp.Panels(1).LoadLayout("Postavke")
    vp.Panels(2).LoadLayout("Login")
    bar.Initialize("bar")
    bar.Icon = LoadBitmap(File.DirAssets, "ic_action_user.png")
    bar.NavigationMode = bar.NAVIGATION_MODE_TABS
    bar.AddTab("Top proizvodi")
    bar.AddTab("Proizvodi a-z")
    bar.AddTab("Račun")
    bar.ShowUpIndicator = True
    bar.SelectedIndex = currentPage

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.app.ActionBar.setIcon(android.graphics.drawable.Drawable)' on a null object reference

Click to expand...