core: Move TDisplayObject downcast methods to DisplayObject

Calling these methods on concrete `TDisplayObject` types never makes sense,
and defining them directly on `DisplayObject` allows a substantial reduction
in boilerplate.

Author: moulins

core/src/avm1/globals/button.rs

@@ -164,7 +164,7 @@ fn tab_index<'gc>(
     this: Avm1Button<'gc>,
     _activation: &mut Activation<'_, 'gc>,
 ) -> Result<Value<'gc>, Error<'gc>> {
-    if let Some(index) = this.as_interactive().and_then(|this| this.tab_index()) {
+    if let Some(index) = this.tab_index() {
         Ok(Value::Number(index as f64))
     } else {
         Ok(Value::Undefined)
@@ -176,18 +176,16 @@ fn set_tab_index<'gc>(
     activation: &mut Activation<'_, 'gc>,
     value: Value<'gc>,
 ) -> Result<(), Error<'gc>> {
-    if let Some(this) = this.as_interactive() {
-        let value = match value {
-            Value::Undefined | Value::Null => None,
-            Value::Bool(_) | Value::Number(_) => {
-                // FIXME This coercion is not perfect, as it wraps
-                //       instead of falling back to MIN, as FP does
-                let i32_value = value.coerce_to_i32(activation)?;
-                Some(i32_value)
-            }
-            _ => Some(i32::MIN),
-        };
-        this.set_tab_index(value);
-    }
+    let value = match value {
+        Value::Undefined | Value::Null => None,
+        Value::Bool(_) | Value::Number(_) => {
+            // FIXME This coercion is not perfect, as it wraps
+            //       instead of falling back to MIN, as FP does
+            let i32_value = value.coerce_to_i32(activation)?;
+            Some(i32_value)
+        }
+        _ => Some(i32::MIN),
+    };
+    this.set_tab_index(value);
     Ok(())
 }

core/src/avm1/globals/movie_clip.rs

@@ -1793,7 +1793,7 @@ fn tab_index<'gc>(
     this: MovieClip<'gc>,
     _activation: &mut Activation<'_, 'gc>,
 ) -> Result<Value<'gc>, Error<'gc>> {
-    if let Some(index) = this.as_interactive().and_then(|this| this.tab_index()) {
+    if let Some(index) = this.tab_index() {
         Ok(Value::Number(index as f64))
     } else {
         Ok(Value::Undefined)
@@ -1805,18 +1805,16 @@ fn set_tab_index<'gc>(
     activation: &mut Activation<'_, 'gc>,
     value: Value<'gc>,
 ) -> Result<(), Error<'gc>> {
-    if let Some(this) = this.as_interactive() {
-        let value = match value {
-            Value::Undefined | Value::Null => None,
-            Value::Bool(_) | Value::Number(_) => {
-                // FIXME This coercion is not perfect, as it wraps
-                //       instead of falling back to MIN, as FP does
-                let i32_value = value.coerce_to_i32(activation)?;
-                Some(i32_value)
-            }
-            _ => Some(i32::MIN),
-        };
-        this.set_tab_index(value);
-    }
+    let value = match value {
+        Value::Undefined | Value::Null => None,
+        Value::Bool(_) | Value::Number(_) => {
+            // FIXME This coercion is not perfect, as it wraps
+            //       instead of falling back to MIN, as FP does
+            let i32_value = value.coerce_to_i32(activation)?;
+            Some(i32_value)
+        }
+        _ => Some(i32::MIN),
+    };
+    this.set_tab_index(value);
     Ok(())
 }

core/src/avm1/globals/text_field.rs

@@ -882,7 +882,7 @@ pub fn tab_index<'gc>(
     this: EditText<'gc>,
     _activation: &mut Activation<'_, 'gc>,
 ) -> Result<Value<'gc>, Error<'gc>> {
-    if let Some(index) = this.as_interactive().and_then(|this| this.tab_index()) {
+    if let Some(index) = this.tab_index() {
         Ok(Value::Number(index as u32 as f64))
     } else {
         Ok(Value::Undefined)
@@ -894,19 +894,17 @@ pub fn set_tab_index<'gc>(
     activation: &mut Activation<'_, 'gc>,
     value: Value<'gc>,
 ) -> Result<(), Error<'gc>> {
-    if let Some(this) = this.as_interactive() {
-        let value = match value {
-            Value::Undefined | Value::Null => None,
-            _ => {
-                // `tabIndex` is u32 in TextField, compared to i32 in Button and MovieClip,
-                // but that is only a data representation difference,
-                // as both are interpreted as i32.
-                let u32_value = value.coerce_to_u32(activation)?;
-                Some(u32_value as i32)
-            }
-        };
-        this.set_tab_index(value);
-    }
+    let value = match value {
+        Value::Undefined | Value::Null => None,
+        _ => {
+            // `tabIndex` is u32 in TextField, compared to i32 in Button and MovieClip,
+            // but that is only a data representation difference,
+            // as both are interpreted as i32.
+            let u32_value = value.coerce_to_u32(activation)?;
+            Some(u32_value as i32)
+        }
+    };
+    this.set_tab_index(value);
     Ok(())
 }
 

core/src/avm1/globals/video.rs

@@ -6,7 +6,7 @@ use crate::avm1::object::NativeObject;
 use crate::avm1::property_decl::{define_properties_on, Declaration};
 use crate::avm1::value::Value;
 use crate::avm1::Object;
-use crate::display_object::{TDisplayObject, Video};
+use crate::display_object::Video;
 use crate::string::StringContext;
 
 macro_rules! video_method {

core/src/avm2/globals/flash/display/bitmap.rs

@@ -13,7 +13,7 @@ use crate::avm2::error::make_error_2008;
 use crate::avm2::parameters::ParametersExt;
 use crate::bitmap::bitmap_data::BitmapDataWrapper;
 use crate::character::Character;
-use crate::display_object::{Bitmap, TDisplayObject};
+use crate::display_object::Bitmap;
 
 pub fn bitmap_allocator<'gc>(
     class: ClassObject<'gc>,

core/src/avm2/globals/flash/display/bitmap_data.rs

@@ -22,7 +22,6 @@ use crate::bitmap::bitmap_data::{
 use crate::bitmap::bitmap_data::{BitmapDataDrawError, IBitmapDrawable};
 use crate::bitmap::{is_size_valid, operations};
 use crate::character::{Character, CompressedBitmap};
-use crate::display_object::TDisplayObject;
 use crate::ecma_conversions::round_to_even;
 use crate::swf::BlendMode;
 use gc_arena::GcCell;

core/src/avm2/globals/flash/display/interactive_object.rs

@@ -5,7 +5,7 @@ use crate::avm2::error::make_error_2027;
 use crate::avm2::parameters::ParametersExt;
 use crate::avm2::value::Value;
 use crate::avm2::Error;
-use crate::display_object::{TDisplayObject, TInteractiveObject};
+use crate::display_object::TInteractiveObject;
 
 /// Implements `InteractiveObject.mouseEnabled`'s getter.
 pub fn get_mouse_enabled<'gc>(

core/src/avm2/globals/flash/display/movie_clip.rs

@@ -7,7 +7,7 @@ use crate::avm2::object::ArrayObject;
 use crate::avm2::parameters::ParametersExt;
 use crate::avm2::value::Value;
 use crate::avm2::Error;
-use crate::display_object::{MovieClip, Scene, TDisplayObject};
+use crate::display_object::{MovieClip, Scene};
 use crate::string::{AvmString, WString};
 
 /// Implements `addFrameScript`, an undocumented method of `MovieClip` used to

core/src/avm2/globals/flash/media/video.rs

@@ -3,7 +3,7 @@ use crate::avm2::globals::flash::display::display_object::initialize_for_allocat
 use crate::avm2::parameters::ParametersExt;
 use crate::avm2::{Activation, ClassObject, Object, Value};
 use crate::avm2_stub_method;
-use crate::display_object::{TDisplayObject, Video};
+use crate::display_object::Video;
 
 pub fn video_allocator<'gc>(
     class: ClassObject<'gc>,

core/src/avm2/globals/flash/text/engine/text_line.rs

@@ -1,7 +1,6 @@
 use crate::avm2::activation::Activation;
 use crate::avm2::error::Error;
 use crate::avm2::value::Value;
-use crate::display_object::TDisplayObject;
 
 pub fn get_text_width<'gc>(
     activation: &mut Activation<'_, 'gc>,