From 047c67baf31cf9bcdc6f0275037bb3b56f2bd268 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E3=81=88=E3=81=A1=E3=82=87?= <dot.station@gmail.com>
Date: Fri, 22 Jun 2018 10:33:29 +0900
Subject: [PATCH] windows feature WS_EX_NOREDIRECTIONBITMAP (#575)

* set WS_EX_NOREDIRECTIONBITMAP

* add CHANGELOG.md

* more flexibility.

* Skip DwmEnableBlurBehindWindow if no_redirection_bitmap is enabled.
---
 CHANGELOG.md                   | 1 +
 src/os/windows.rs              | 9 +++++++++
 src/platform/windows/mod.rs    | 1 +
 src/platform/windows/window.rs | 5 ++++-
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c6bca654..19104a52 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 # Unreleased
 
+- Windows additionally has `WindowBuilderExt::with_no_redirection_bitmap`.
 - **Breaking:** Removed `VirtualKeyCode::LMenu` and `VirtualKeyCode::RMenu`; Windows now generates `VirtualKeyCode::LAlt` and `VirtualKeyCode::RAlt` instead.
 - On X11, exiting fullscreen no longer leaves the window in the monitor's top left corner.
 - **Breaking:** `Window::hidpi_factor` has been renamed to `Window::get_hidpi_factor` for better consistency. `WindowEvent::HiDPIFactorChanged` has been renamed to `WindowEvent::HiDpiFactorChanged`. DPI factors are always represented as `f64` instead of `f32` now.
diff --git a/src/os/windows.rs b/src/os/windows.rs
index d9f427b2..62b16c7a 100644
--- a/src/os/windows.rs
+++ b/src/os/windows.rs
@@ -55,6 +55,9 @@ pub trait WindowBuilderExt {
 
     /// This sets `ICON_BIG`. A good ceiling here is 256x256.
     fn with_taskbar_icon(self, taskbar_icon: Option<Icon>) -> WindowBuilder;
+
+    /// This sets `WS_EX_NOREDIRECTIONBITMAP`.
+    fn with_no_redirection_bitmap(self, flag: bool) -> WindowBuilder;
 }
 
 impl WindowBuilderExt for WindowBuilder {
@@ -69,6 +72,12 @@ impl WindowBuilderExt for WindowBuilder {
         self.platform_specific.taskbar_icon = taskbar_icon;
         self
     }
+
+    #[inline]
+    fn with_no_redirection_bitmap(mut self, flag: bool) -> WindowBuilder {
+        self.platform_specific.no_redirection_bitmap = flag;
+        self
+    }
 }
 
 /// Additional methods on `MonitorId` that are specific to Windows.
diff --git a/src/platform/windows/mod.rs b/src/platform/windows/mod.rs
index 69c96d68..bd16c743 100644
--- a/src/platform/windows/mod.rs
+++ b/src/platform/windows/mod.rs
@@ -11,6 +11,7 @@ pub use self::window::Window;
 pub struct PlatformSpecificWindowBuilderAttributes {
     pub parent: Option<HWND>,
     pub taskbar_icon: Option<::Icon>,
+    pub no_redirection_bitmap: bool,
 }
 
 unsafe impl Send for PlatformSpecificWindowBuilderAttributes {}
diff --git a/src/platform/windows/window.rs b/src/platform/windows/window.rs
index 385fbe6d..8dedc2ff 100644
--- a/src/platform/windows/window.rs
+++ b/src/platform/windows/window.rs
@@ -888,6 +888,9 @@ unsafe fn init(
     if attributes.always_on_top {
         ex_style |= winuser::WS_EX_TOPMOST;
     }
+    if pl_attribs.no_redirection_bitmap {
+        ex_style |= winuser::WS_EX_NOREDIRECTIONBITMAP;
+    }
 
     // adjusting the window coordinates using the style
     winuser::AdjustWindowRectEx(&mut rect, style, 0, ex_style);
@@ -999,7 +1002,7 @@ unsafe fn init(
     };
 
     // making the window transparent
-    if attributes.transparent {
+    if attributes.transparent && !pl_attribs.no_redirection_bitmap {
         let bb = dwmapi::DWM_BLURBEHIND {
             dwFlags: 0x1, // FIXME: DWM_BB_ENABLE;
             fEnable: 1,