Customizing window decorations

How can I customize window decorations in SDL2?

SDL2 itself does not provide direct support for customizing window decorations (title bar, borders, etc.). It only allows enabling or disabling decorations using the SDL_WINDOW_BORDERLESS flag.

For advanced customization, such as changing the appearance of the title bar or borders, you'll need to use platform-specific APIs outside of SDL2.

Custom Decorations with SDL2

One common approach is to create a borderless window (SDL_WINDOW_BORDERLESS) and then draw custom decorations within the client area using SDL's rendering functions.

This gives you full control over the appearance and functionality of the decorations. Here's an example:

#include <SDL.h>
#include <iostream>

void RenderCustomDecorations(
  SDL_Renderer* Renderer,
  int Width,
  int Height
) {
  // Draw a custom title bar
  SDL_Rect TitleBar{0, 0, Width, 30};

  SDL_SetRenderDrawColor(Renderer,
    50, 50, 50, 255); // Dark gray
  SDL_RenderFillRect(Renderer, &TitleBar);

  // Draw a close button
  SDL_Rect CloseButton{Width - 30, 0, 30, 30};

  SDL_SetRenderDrawColor(Renderer,
    200, 50, 50, 255); // Red
  SDL_RenderFillRect(Renderer, &CloseButton);
}

int main() {
  SDL_Init(SDL_INIT_VIDEO);

  SDL_Window* Window{
    SDL_CreateWindow(
      "Custom Decorations",
      SDL_WINDOWPOS_CENTERED,
      SDL_WINDOWPOS_CENTERED,
      800, 600,
      SDL_WINDOW_BORDERLESS 
    )};
  SDL_Renderer* Renderer{
    SDL_CreateRenderer(
      Window, -1, SDL_RENDERER_ACCELERATED)};

  bool Running{true};
  SDL_Event Event;
  while (Running) {
    while (SDL_PollEvent(&Event)) {
      if (Event.type == SDL_QUIT) {
        Running = false;
      } else if (
        Event.type == SDL_MOUSEBUTTONDOWN
      ) {
        int MouseX = Event.button.x;
        int MouseY = Event.button.y;

        // Detect click on the close button
        if (MouseX >= 770 && MouseY <= 30) {
          
          Running = false;
        }
      }
    }

    // Render custom decorations
    SDL_SetRenderDrawColor(Renderer,
      0, 0, 0, 255); // Black background
    
    SDL_RenderClear(Renderer);
    RenderCustomDecorations(Renderer, 800, 600);
    SDL_RenderPresent(Renderer);
  }

  SDL_DestroyRenderer(Renderer);
  SDL_DestroyWindow(Window);
  SDL_Quit();
}

This example simulates a title bar with a close button, allowing you to customize the appearance as needed.

Using Platform-Specific APIs

For greater flexibility, you can modify the window style directly through platform-specific APIs. For example:

  • Windows (Win32 API): Use SetWindowLongPtr to modify the window style and remove specific decorations, such as the title bar, while keeping borders.
  • Linux (X11): Use XChangeProperty or related functions to interact with the window manager.
  • macOS (Cocoa): Use Objective-C APIs to customize window properties.

However, these approaches require writing separate code for each platform, which can complicate cross-platform projects.

Libraries for Custom Windowing

Another option is to use libraries like Dear ImGui or Qt for more advanced window customization. These libraries offer higher-level abstractions and more features for creating custom-styled windows.

For most SDL2 projects, using a borderless window with custom rendering is the simplest way to achieve custom decorations without breaking cross-platform compatibility.

Window Decorations and Borders

An introduction to managing SDL2 window decorations, borders, and client areas.

Questions & Answers

Answers are generated by AI models and may not have been reviewed. Be mindful when running any code on your device.

Why use a borderless window?
Why would you want a borderless window in an application?
Can SDL customize border colors?
Can I change the color of the border or title bar in SDL2?
Borderless and SDL_GetWindowBordersSize()
How does SDL_GetWindowBordersSize() behave on borderless windows?
Uses of window decoration sizes
What are some practical uses for knowing the size of window decorations?
Resizable borderless windows in SDL2
Can I create a borderless window that still has a resizable frame?
Decorations in fullscreen modes
How do window decorations affect fullscreen modes?
Can I remove only the title bar?
Can I remove only the title bar but keep the borders?
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