feat: update file activity UI

Update the file activity UI with the following changes:

- Enable edge-to-edge display.
- Add a toolbar and set it as the action bar.
- Update the TreeView padding to account for system bars.
- Update the checkable view to be a MaterialCheckBox.
- Simplify onClick to only show a toast with the node name.
- Update onRefresh to not display a toast.

app/src/main/kotlin/com/dingyi/treeview/FileActivity.kt

@@ -15,9 +15,13 @@ import android.view.ViewGroup
 import android.widget.Checkable
 import android.widget.Space
 import android.widget.Toast
+import androidx.activity.enableEdgeToEdge
 import androidx.appcompat.app.AppCompatActivity
+import androidx.core.view.ViewCompat
+import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.isVisible
 import androidx.core.view.updateLayoutParams
+import androidx.core.view.updatePadding
 import androidx.lifecycle.lifecycleScope
 import com.dingyi.treeview.databinding.ActivityMainBinding
 import com.dingyi.treeview.databinding.ItemDirBinding
@@ -49,10 +53,20 @@ class FileActivity : AppCompatActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
+        enableEdgeToEdge()
+
         binding = ActivityMainBinding.inflate(layoutInflater)
         fileListLoader = FileListLoader()
         setContentView(binding.root)
 
+        setSupportActionBar(binding.toolbar)
+
+        ViewCompat.setOnApplyWindowInsetsListener(binding.treeview) { view, windowInsets ->
+            val insets = windowInsets.getInsets(WindowInsetsCompat.Type.systemBars())
+            view.updatePadding(bottom = insets.bottom)
+            windowInsets
+        }
+
         requestStoragePermission()
 
         if (!hasStoragePermission) {
@@ -226,7 +240,7 @@ class FileActivity : AppCompatActivity() {
                 width = node.depth * 22.dp
             }
 
-            (getCheckableView(node, holder) as MaterialCheckBox).apply {
+            (getCheckableView(node, holder)).apply {
                 isVisible = node.selected
                 isSelected = node.selected
             }
@@ -254,7 +268,7 @@ class FileActivity : AppCompatActivity() {
         override fun getCheckableView(
             node: TreeNode<File>,
             holder: TreeView.ViewHolder
-        ): Checkable {
+        ): MaterialCheckBox {
             return if (node.isChild) {
                 ItemDirBinding.bind(holder.itemView).checkbox
             } else {
@@ -263,12 +277,8 @@ class FileActivity : AppCompatActivity() {
         }
 
         override fun onClick(node: TreeNode<File>, holder: TreeView.ViewHolder) {
-            if (node.isChild) {
-                applyDir(holder, node)
-            } else {
-                Toast.makeText(holder.itemView.context, "Clicked ${node.name}", Toast.LENGTH_LONG)
-                    .show()
-            }
+            Toast.makeText(holder.itemView.context, "Clicked ${node.name}", Toast.LENGTH_LONG)
+                .show()
         }
 
         override fun onRefresh(status: Boolean) {