core: Add FocusTracker.get_as_edit_text method

This is a utility method which simplifies getting the current focus
as an EditText object, which is being done frequently throughout Ruffle.

core/src/avm1/globals/selection.rs

@@ -23,8 +23,7 @@ pub fn get_begin_index<'gc>(
     if let Some(selection) = activation
         .context
         .focus_tracker
-        .get()
-        .and_then(|o| o.as_edit_text())
+        .get_as_edit_text()
         .and_then(EditText::selection)
     {
         Ok(selection.start().into())
@@ -41,8 +40,7 @@ pub fn get_end_index<'gc>(
     if let Some(selection) = activation
         .context
         .focus_tracker
-        .get()
-        .and_then(|o| o.as_edit_text())
+        .get_as_edit_text()
         .and_then(EditText::selection)
     {
         Ok(selection.end().into())
@@ -59,8 +57,7 @@ pub fn get_caret_index<'gc>(
     if let Some(selection) = activation
         .context
         .focus_tracker
-        .get()
-        .and_then(|o| o.as_edit_text())
+        .get_as_edit_text()
         .and_then(EditText::selection)
     {
         Ok(selection.to().into())
@@ -78,12 +75,7 @@ pub fn set_selection<'gc>(
         return Ok(Value::Undefined);
     }
 
-    if let Some(edit_box) = activation
-        .context
-        .focus_tracker
-        .get()
-        .and_then(|o| o.as_edit_text())
-    {
+    if let Some(edit_box) = activation.context.focus_tracker.get_as_edit_text() {
         let start = args
             .get(0)
             .map(|v| v.coerce_to_i32(activation))

core/src/focus_tracker.rs

@@ -1,10 +1,10 @@
 use crate::avm1::Avm1;
 use crate::avm1::Value;
 use crate::context::{RenderContext, UpdateContext};
-use crate::display_object::TInteractiveObject;
 pub use crate::display_object::{
     DisplayObject, TDisplayObject, TDisplayObjectContainer, TextSelection,
 };
+use crate::display_object::{EditText, TInteractiveObject};
 use crate::drawing::Drawing;
 use either::Either;
 use gc_arena::barrier::unlock;
@@ -60,6 +60,10 @@ impl<'gc> FocusTracker<'gc> {
         self.0.focus.get()
     }
 
+    pub fn get_as_edit_text(&self) -> Option<EditText<'gc>> {
+        self.get().and_then(|o| o.as_edit_text())
+    }
+
     pub fn set(
         &self,
         focused_element: Option<DisplayObject<'gc>>,
@@ -99,7 +103,7 @@ impl<'gc> FocusTracker<'gc> {
         }
 
         // This applies even if the focused element hasn't changed.
-        if let Some(text_field) = focused_element.and_then(|e| e.as_edit_text()) {
+        if let Some(text_field) = self.get_as_edit_text() {
             if text_field.is_editable() {
                 if !text_field.movie().is_action_script_3() {
                     let length = text_field.text_length();

core/src/player.rs

@@ -1060,12 +1060,12 @@ impl Player {
             // keyPress events take precedence over text input.
             if !key_press_handled {
                 if let PlayerEvent::TextInput { codepoint } = event {
-                    if let Some(text) = context.focus_tracker.get().and_then(|o| o.as_edit_text()) {
+                    if let Some(text) = context.focus_tracker.get_as_edit_text() {
                         text.text_input(codepoint, context);
                     }
                 }
                 if let PlayerEvent::TextControl { code } = event {
-                    if let Some(text) = context.focus_tracker.get().and_then(|o| o.as_edit_text()) {
+                    if let Some(text) = context.focus_tracker.get_as_edit_text() {
                         text.text_control_input(code, context);
                     }
                 }