How to hide menu item at specific tab, tabbed activity, Kotlin

Question

Assume different menuicons are to be displayed on the toolbar of a tabbed activity at different tabs.

One solution is to build a distinct menu for each fragment/tab and inflate at the corresponding onCreateOptionsMenu() function. However, this solution is proven to be slow and lagging. Menuicons does not disappear fast enough.

The second solution is to inflate all menuicons in the "activity" and then hide when necessary. This option is faster.

I tried pageChangeListener and tabSelectedListener. But somehow menuicons did not disapear at first click. They disappear after both hiding tabs are clicked in row. If invalidateOptionsMenu() used, menuicons are NOT hidden at all.

Do you have an idea why this happens? Or do you have another fast method to hide the icons?

Here is the related code:

override fun onCreateOptionsMenu(menu: Menu?): Boolean {
    Log.v("MainAct", "MainAct onCreateOptionsMenu")

    menuInflater.inflate(R.menu.mainmenu, menu)

    viewPager.addOnPageChangeListener(object : ViewPager.SimpleOnPageChangeListener() {


        override fun onPageSelected(position: Int) {
            when (position) {
                0 -> {
                    menu!!.findItem(R.id.menuicon_contacts).isVisible = false
                    menu.findItem(R.id.menuicon_add).isVisible = false
                    invalidateOptionsMenu() // With this line menuicons does not disappear at all
                }
                1 -> {
                    menu!!.findItem(R.id.menuicon_contacts).isVisible = false
                    menu.findItem(R.id.menuicon_add).isVisible = false
                    invalidateOptionsMenu()

                }
                2 -> {
                    menu!!.findItem(R.id.menuicon_contacts).isVisible = true
                    menu.findItem(R.id.menuicon_add).isVisible = true
                    invalidateOptionsMenu()

                }
            }
        }

    })

    return super.onCreateOptionsMenu(menu)
}

You can create different menus. then recreat the main menu on page selected. — Kasım Özdemir, Mar 08 '20 at 07:04
When I did that inside fragments' `onCreateOptionsMenu()` it was slow to hide. Do you suggest setting the listener inside `onCreateOptionsMenu()` of the 'Activity' and calling one of 3 different menu layouts accordingly? — Xfce4, Mar 08 '20 at 07:10
The listener should be outside onCreateOptionsMenu(). Create 3 different menus and define menu types. Select type onPageSelected and call invalidateOptionsMenu(). — Kasım Özdemir, Mar 08 '20 at 07:23
How to reach the `menu` parameter outside `onCreateOptionsMenu()`? — Xfce4, Mar 08 '20 at 07:39
You can use onOptionsItemSelected(MenuItem item) method. You won't need to check visible when you create 3 different menus — Kasım Özdemir, Mar 08 '20 at 07:49

score 0 · Accepted Answer · answered Mar 08 '20 at 18:37

var menu1 : Boolean = true

onCreate method:

viewPager.addOnPageChangeListener(object : ViewPager.SimpleOnPageChangeListener() {

    override fun onPageSelected(position: Int) {
        when (position) {
            0 -> {
                menu1 = true
                invalidateOptionsMenu() 
            }
            1 -> {
                menu1 = true
                invalidateOptionsMenu()

            }
            2 -> {
                menu1 = false
                invalidateOptionsMenu()

            }
        }
    }

})

override methods:

override fun onCreateOptionsMenu(menu: Menu?): Boolean {
if(menu1){
   menuInflater.inflate(R.menu.mainmenu1, menu)
}else{
   menuInflater.inflate(R.menu.mainmenu2, menu)
}

return super.onCreateOptionsMenu(menu)
}

override fun onOptionsItemSelected(item: MenuItem): Boolean {
    when (item.itemId) {
        R.id.menuicon_contacts -> {
            // your code
            return true
        }
        R.id.menuicon_add -> {
            // your code
            return true
        }
    }
    return super.onOptionsItemSelected(item)
}

Thank you. Works and fast enough in my case. – Xfce4 Mar 08 '20 at 19:13 — Xfce4, Mar 08 '20 at 19:13

How to hide menu item at specific tab, tabbed activity, Kotlin

1 Answers1