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.