implement root file creation

app/src/main/kotlin/com/simplemobiletools/filemanager/dialogs/CreateNewItemDialog.kt

@@ -2,14 +2,15 @@ package com.simplemobiletools.filemanager.dialogs
 
 import android.support.v7.app.AlertDialog
 import android.view.View
-import com.simplemobiletools.commons.activities.BaseSimpleActivity
 import com.simplemobiletools.commons.extensions.*
 import com.simplemobiletools.filemanager.R
+import com.simplemobiletools.filemanager.activities.SimpleActivity
+import com.simplemobiletools.filemanager.helpers.RootHelpers
 import kotlinx.android.synthetic.main.dialog_create_new.view.*
 import java.io.File
 import java.io.IOException
 
-class CreateNewItemDialog(val activity: BaseSimpleActivity, val path: String, val callback: (success: Boolean) -> Unit) {
+class CreateNewItemDialog(val activity: SimpleActivity, val path: String, val callback: (success: Boolean) -> Unit) {
     private val view = activity.layoutInflater.inflate(R.layout.dialog_create_new, null)
 
     init {
@@ -60,16 +61,18 @@ class CreateNewItemDialog(val activity: BaseSimpleActivity, val path: String, va
                 documentFile.createDirectory(path.getFilenameFromPath())
                 success(alertDialog)
             }
-            File(path).mkdirs() -> {
+            path.startsWith(activity.internalStoragePath, true) -> {
+                if (File(path).mkdirs()) {
                     success(alertDialog)
                 }
-            else -> callback(false)
+            }
         }
     }
 
     private fun createFile(path: String, alertDialog: AlertDialog, callback: (Boolean) -> Unit) {
         try {
-            if (activity.needsStupidWritePermissions(path)) {
+            when {
+                activity.needsStupidWritePermissions(path) -> {
                     activity.handleSAFDialog(path) {
                         val documentFile = activity.getDocumentFile(path.getParentPath())
                         if (documentFile == null) {
@@ -81,9 +84,22 @@ class CreateNewItemDialog(val activity: BaseSimpleActivity, val path: String, va
                         documentFile.createFile(path.getMimeType(), path.getFilenameFromPath())
                         success(alertDialog)
                     }
-            } else if (File(path).createNewFile()) {
+                }
+                path.startsWith(activity.internalStoragePath, true) -> {
+                    if (File(path).createNewFile()) {
                         success(alertDialog)
                     }
+                }
+                else -> {
+                    RootHelpers().createFile(activity, path) {
+                        if (it) {
+                            success(alertDialog)
+                        } else {
+                            callback(false)
+                        }
+                    }
+                }
+            }
         } catch (exception: IOException) {
             activity.showErrorToast(exception)
             callback(false)

app/src/main/kotlin/com/simplemobiletools/filemanager/helpers/RootHelpers.kt

@@ -129,4 +129,82 @@ class RootHelpers {
             activity.showErrorToast(e)
         }
     }
+
+    fun createFile(activity: SimpleActivity, path: String, callback: (success: Boolean) -> Unit) {
+        tryMountAsRW(activity, path) {
+            val mountPoint = it
+            val targetPath = path.trim('/')
+            val cmd = "touch \"/$targetPath\""
+            val command = object : Command(0, cmd) {
+                override fun commandCompleted(id: Int, exitcode: Int) {
+                    callback(exitcode == 0)
+                    mountAsRO(activity, mountPoint)
+                    super.commandCompleted(id, exitcode)
+                }
+            }
+
+            runCommand(activity, command)
+        }
+    }
+
+    private fun mountAsRO(activity: SimpleActivity, mountPoint: String?) {
+        if (mountPoint != null) {
+            val cmd = "umount -r \"$mountPoint\""
+            val command = object : Command(0, cmd) {}
+            runCommand(activity, command)
+        }
+    }
+
+    // inspired by Amaze File Manager
+    private fun tryMountAsRW(activity: SimpleActivity, path: String, callback: (mountPoint: String?) -> Unit) {
+        val mountPoints = ArrayList<String>()
+
+        val command = object : Command(0, "mount") {
+            override fun commandOutput(id: Int, line: String) {
+                mountPoints.add(line)
+                super.commandOutput(id, line)
+            }
+
+            override fun commandCompleted(id: Int, exitcode: Int) {
+                var mountPoint = ""
+                var types: String? = null
+                for (line in mountPoints) {
+                    val words = line.split(" ").filter { it.isNotEmpty() }
+
+                    if (path.contains(words[2])) {
+                        if (words[2].length > mountPoint.length) {
+                            mountPoint = words[2]
+                            types = words[5]
+                        }
+                    }
+                }
+
+                if (mountPoint != "" && types != null) {
+                    if (types.contains("rw")) {
+                        callback(null)
+                    } else if (types.contains("ro")) {
+                        val mountCommand = "mount -o rw,remount $mountPoint"
+                        mountAsRW(activity, mountCommand) {
+                            callback(it)
+                        }
+                    }
+                }
+
+                super.commandCompleted(id, exitcode)
+            }
+        }
+
+        runCommand(activity, command)
+    }
+
+    private fun mountAsRW(activity: SimpleActivity, commandString: String, callback: (mountPoint: String) -> Unit) {
+        val command = object : Command(0, commandString) {
+            override fun commandOutput(id: Int, line: String) {
+                callback(line)
+                super.commandOutput(id, line)
+            }
+        }
+
+        runCommand(activity, command)
+    }
 }