get rid of some warnings

src/framework/backend.rs

@@ -60,6 +60,8 @@ pub trait BackendRenderer {
 
     fn imgui_texture_id(&self, texture: &Box<dyn BackendTexture>) -> GameResult<imgui::TextureId>;
 
+    fn prepare_imgui(&mut self, ui: &imgui::Ui) -> GameResult;
+
     fn render_imgui(&mut self, draw_data: &DrawData) -> GameResult;
 
     fn supports_vertex_draw(&self) -> bool {

src/framework/backend_null.rs

@@ -2,7 +2,7 @@ use std::any::Any;
 use std::cell::RefCell;
 use std::mem;
 
-use imgui::{DrawData, TextureId};
+use imgui::{DrawData, TextureId, Ui};
 
 use crate::common::{Color, Rect};
 use crate::framework::backend::{
@@ -135,6 +135,10 @@ impl BackendRenderer for NullRenderer {
         Ok(TextureId::from(0))
     }
 
+    fn prepare_imgui(&mut self, _ui: &Ui) -> GameResult {
+        Ok(())
+    }
+
     fn render_imgui(&mut self, _draw_data: &DrawData) -> GameResult {
         Ok(())
     }

src/framework/backend_sdl2.rs

@@ -8,7 +8,7 @@ use std::rc::Rc;
 use std::time::Duration;
 
 use imgui::internal::RawWrapper;
-use imgui::{ConfigFlags, DrawCmd, DrawData, Key, MouseCursor, TextureId};
+use imgui::{ConfigFlags, DrawCmd, DrawData, Key, MouseCursor, TextureId, Ui};
 use sdl2::event::{Event, WindowEvent};
 use sdl2::keyboard::Scancode;
 use sdl2::mouse::{Cursor, SystemCursor};
@@ -602,6 +602,13 @@ impl BackendRenderer for SDL2Renderer {
         Ok(TextureId::new(sdl_texture.texture.as_ref().map(|t| t.raw()).unwrap_or(null_mut()) as usize))
     }
 
+    fn prepare_imgui(&mut self, ui: &Ui) -> GameResult {
+        let refs = self.refs.borrow_mut();
+        self.imgui_event.borrow_mut().prepare_render(ui, refs.canvas.window());
+
+        Ok(())
+    }
+
     fn render_imgui(&mut self, draw_data: &DrawData) -> GameResult {
         let mut refs = self.refs.borrow_mut();
 
@@ -1100,6 +1107,10 @@ impl ImguiSdl2 {
             imgui.io_mut().key_super = super_;
         }
 
+        if self.ignore_event(event) {
+            return;
+        }
+
         match *event {
             Event::MouseWheel { y, .. } => {
                 imgui.io_mut().mouse_wheel = y as f32;

src/framework/graphics.rs

@@ -128,6 +128,14 @@ pub fn imgui_texture_id(ctx: &Context, texture: &Box<dyn BackendTexture>) -> Gam
     Err(GameError::RenderError("Rendering backend hasn't been initialized yet.".to_string()))
 }
 
+pub fn prepare_imgui(ctx: &mut Context, ui: &imgui::Ui) -> GameResult {
+    if let Some(renderer) = ctx.renderer.as_mut() {
+        return renderer.prepare_imgui(ui);
+    }
+
+    Err(GameError::RenderError("Rendering backend hasn't been initialized yet.".to_string()))
+}
+
 pub fn render_imgui(ctx: &mut Context, draw_data: &imgui::DrawData) -> GameResult {
     if let Some(renderer) = ctx.renderer.as_mut() {
         return renderer.render_imgui(draw_data);

src/framework/mod.rs

@@ -1,3 +1,5 @@
+#![allow(unused)]
+
 pub mod backend;
 pub mod backend_null;
 #[cfg(feature = "backend-glutin")]

src/framework/render_opengl.rs

@@ -6,7 +6,7 @@ use std::mem::MaybeUninit;
 use std::ptr::null;
 use std::sync::Arc;
 
-use imgui::{DrawCmd, DrawCmdParams, DrawData, DrawIdx, DrawVert, TextureId};
+use imgui::{DrawCmd, DrawCmdParams, DrawData, DrawIdx, DrawVert, TextureId, Ui};
 
 use crate::common::{Color, Rect};
 use crate::framework::backend::{BackendRenderer, BackendShader, BackendTexture, SpriteBatchCommand, VertexData};
@@ -1053,6 +1053,10 @@ impl BackendRenderer for OpenGLRenderer {
         Ok(TextureId::new(gl_texture.texture_id as usize))
     }
 
+    fn prepare_imgui(&mut self, _ui: &Ui) -> GameResult {
+        Ok(())
+    }
+
     fn render_imgui(&mut self, draw_data: &DrawData) -> GameResult {
         // https://github.com/michaelfairley/rust-imgui-opengl-renderer
         if let Some((_, gl)) = self.get_context() {

src/framework/ui.rs

@@ -6,6 +6,7 @@ use imgui::sys::*;
 use crate::framework::context::Context;
 use crate::framework::error::GameResult;
 use crate::framework::graphics::{imgui_context, render_imgui};
+use crate::graphics::prepare_imgui;
 use crate::live_debugger::LiveDebugger;
 use crate::scene::Scene;
 use crate::shared_game_state::SharedGameState;
@@ -128,6 +129,7 @@ impl UI {
 
         scene.imgui_draw(&mut self.components, state, ctx2, &mut ui)?;
 
+        prepare_imgui(ctx2, &ui);
         let draw_data = ui.render();
         render_imgui(ctx2, draw_data)?;