allow changing the column count with menu buttons

app/src/main/kotlin/com/simplemobiletools/applauncher/activities/MainActivity.kt

@@ -19,10 +19,13 @@ import com.simplemobiletools.commons.helpers.ensureBackgroundThread
 import com.simplemobiletools.commons.interfaces.RefreshRecyclerViewListener
 import com.simplemobiletools.commons.models.FAQItem
 import com.simplemobiletools.commons.models.Release
+import com.simplemobiletools.commons.views.MyGridLayoutManager
 import kotlinx.android.synthetic.main.activity_main.*
 import java.util.*
 
 class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
+    private val MAX_COLUMN_COUNT = 20
+
     private var displayedLaunchers = ArrayList<AppLauncher>()
     private var notDisplayedLaunchers: ArrayList<AppLauncher>? = null
     private var mStoredPrimaryColor = 0
@@ -35,6 +38,7 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
         setupLaunchers()
         checkWhatsNewDialog()
         storeStateVariables()
+        setupGridLayoutManager()
 
         fab.setOnClickListener {
             if (notDisplayedLaunchers != null) {
@@ -78,6 +82,8 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         when (item.itemId) {
+            R.id.increase_column_count -> increaseColumnCount()
+            R.id.reduce_column_count -> reduceColumnCount()
             R.id.settings -> launchSettings()
             R.id.about -> launchAbout()
             else -> return super.onOptionsItemSelected(item)
@@ -135,6 +141,37 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
         }
     }
 
+    private fun increaseColumnCount() {
+        config.columnCnt = ++(launchers_grid.layoutManager as MyGridLayoutManager).spanCount
+        columnCountChanged()
+    }
+
+    private fun reduceColumnCount() {
+        config.columnCnt = --(launchers_grid.layoutManager as MyGridLayoutManager).spanCount
+        columnCountChanged()
+    }
+
+    private fun columnCountChanged() {
+        invalidateOptionsMenu()
+        launchers_grid.adapter?.notifyDataSetChanged()
+        getGridAdapter()?.launchers?.apply {
+            calculateContentHeight(this)
+        }
+    }
+
+    private fun calculateContentHeight(directories: List<AppLauncher>) {
+        val layoutManager = launchers_grid.layoutManager as MyGridLayoutManager
+        val thumbnailHeight = layoutManager.getChildAt(0)?.height ?: 0
+        val fullHeight = ((directories.size - 1) / layoutManager.spanCount + 1) * thumbnailHeight
+        launchers_fastscroller.setContentHeight(fullHeight)
+        launchers_fastscroller.setScrollToY(launchers_grid.computeVerticalScrollOffset())
+    }
+
+    private fun setupGridLayoutManager() {
+        val layoutManager = launchers_grid.layoutManager as MyGridLayoutManager
+        layoutManager.spanCount = config.columnCnt
+    }
+
     private fun checkInvalidApps() {
         val invalidIds = ArrayList<String>()
         for ((id, name, packageName) in displayedLaunchers) {

app/src/main/kotlin/com/simplemobiletools/applauncher/adapters/LaunchersAdapter.kt

@@ -18,7 +18,7 @@ import com.simplemobiletools.commons.views.FastScroller
 import com.simplemobiletools.commons.views.MyRecyclerView
 import kotlinx.android.synthetic.main.item_app_launcher.view.*
 
-class LaunchersAdapter(activity: SimpleActivity, val launchers: MutableList<AppLauncher>, val listener: RefreshRecyclerViewListener?,
+class LaunchersAdapter(activity: SimpleActivity, val launchers: ArrayList<AppLauncher>, val listener: RefreshRecyclerViewListener?,
                        recyclerView: MyRecyclerView, fastScroller: FastScroller, itemClick: (Any) -> Unit) :
         MyRecyclerViewAdapter(activity, recyclerView, fastScroller, itemClick) {
 

app/src/main/kotlin/com/simplemobiletools/applauncher/helpers/Config.kt

@@ -1,6 +1,7 @@
 package com.simplemobiletools.applauncher.helpers
 
 import android.content.Context
+import com.simplemobiletools.applauncher.R
 import com.simplemobiletools.commons.helpers.BaseConfig
 
 class Config(context: Context) : BaseConfig(context) {
@@ -15,4 +16,8 @@ class Config(context: Context) : BaseConfig(context) {
     var closeApp: Boolean
         get() = prefs.getBoolean(CLOSE_APP, true)
         set(closeApp) = prefs.edit().putBoolean(CLOSE_APP, closeApp).apply()
+
+    var columnCnt: Int
+        get() = prefs.getInt(COLUMN_CNT, context.resources.getInteger(R.integer.column_count))
+        set(columnCnt) = prefs.edit().putInt(COLUMN_CNT, columnCnt).apply()
 }

app/src/main/kotlin/com/simplemobiletools/applauncher/helpers/Constants.kt

@@ -2,6 +2,7 @@ package com.simplemobiletools.applauncher.helpers
 
 const val WAS_REMOVE_INFO_SHOWN = "was_remove_info_shown"
 const val CLOSE_APP = "close_app"
+const val COLUMN_CNT = "column_cnt"
 
 val predefinedPackageNames = arrayListOf(
     "com.simplemobiletools.calculator",

app/src/main/res/layout/activity_main.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<androidx.coordinatorlayout.widget.CoordinatorLayout
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/coordinator_layout"
     android:layout_width="match_parent"
@@ -16,18 +15,18 @@
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             android:clipToPadding="false"
-            android:paddingBottom="@dimen/activity_margin"
             android:paddingTop="@dimen/activity_margin"
+            android:paddingBottom="@dimen/activity_margin"
             app:layoutManager="com.simplemobiletools.commons.views.MyGridLayoutManager"
-            app:spanCount="@integer/columns"/>
+            app:spanCount="@integer/column_count" />
 
         <com.simplemobiletools.commons.views.FastScroller
             android:id="@+id/launchers_fastscroller"
             android:layout_width="wrap_content"
             android:layout_height="match_parent"
+            android:layout_alignTop="@+id/launchers_grid"
             android:layout_alignBottom="@+id/launchers_grid"
             android:layout_alignParentEnd="true"
-            android:layout_alignTop="@+id/launchers_grid"
             android:paddingStart="@dimen/normal_margin">
 
             <include layout="@layout/fastscroller_handle_vertical" />

app/src/main/res/layout/dialog_pick_launchers.xml

@@ -8,4 +8,4 @@
     android:padding="@dimen/small_margin"
     android:scrollbars="vertical"
     app:layoutManager="com.simplemobiletools.commons.views.MyGridLayoutManager"
-    app:spanCount="@integer/columns"/>
+    app:spanCount="@integer/column_count"/>

app/src/main/res/menu/menu.xml

@@ -1,6 +1,14 @@
 <?xml version="1.0" encoding="utf-8"?>
 <menu xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto">
+    <item
+        android:id="@+id/increase_column_count"
+        android:title="@string/increase_column_count"
+        app:showAsAction="never" />
+    <item
+        android:id="@+id/reduce_column_count"
+        android:title="@string/reduce_column_count"
+        app:showAsAction="never" />
     <item
         android:id="@+id/settings"
         android:title="@string/settings"

app/src/main/res/values-sw400dp/integers.xml

@@ -1,3 +1,3 @@
 <resources>
-    <integer name="columns">5</integer>
+    <integer name="column_count">5</integer>
 </resources>

app/src/main/res/values/integers.xml

@@ -1,3 +1,3 @@
 <resources>
-    <integer name="columns">4</integer>
+    <integer name="column_count">4</integer>
 </resources>