Latest SDL API breaks build - The text input state has been changed to be window-specific

[adrian-purser]

Version/Branch of Dear ImGui:

Version 1.90.9, Branch: docking

Back-ends:

imgui_impl_SDL3 + imgui_impl_opengl3

Compiler, OS:

Linux GCC 14.1.1

Full config/build information:

Dear ImGui 1.90.9 WIP (19083)
--------------------------------
sizeof(size_t): 8, sizeof(ImDrawIdx): 2, sizeof(ImDrawVert): 20
define: __cplusplus=202002
define: __linux__
define: __GNUC__=14
define: IMGUI_HAS_VIEWPORT
define: IMGUI_HAS_DOCK
--------------------------------
io.BackendPlatformName: imgui_impl_sdl3
io.BackendRendererName: imgui_impl_opengl3
io.ConfigFlags: 0x00000480
 DockingEnable
 ViewportsEnable
io.ConfigViewportsNoDecoration
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigMemoryCompactTimer = 60.0
io.BackendFlags: 0x00001C0E
 HasMouseCursors
 HasSetMousePos
 PlatformHasViewports
 HasMouseHoveredViewport
 RendererHasVtxOffset
 RendererHasViewports
--------------------------------
io.Fonts: 8 fonts, Flags: 0x00000000, TexSize: 512,1024
io.DisplaySize: 1024.00,768.00
io.DisplayFramebufferScale: 1.00,1.00
--------------------------------
style.WindowPadding: 1.00,1.00
style.WindowBorderSize: 1.00
style.FramePadding: 4.00,3.00
style.FrameRounding: 3.00
style.FrameBorderSize: 0.00
style.ItemSpacing: 8.00,4.00
style.ItemInnerSpacing: 4.00,4.00

Details:

Changes to SDL keyboard code cause the build to fail. The relevant SDL commit is -

The text input state has been changed to be window-specific.
SDL_StartTextInput(), SDL_StopTextInput(), SDL_TextInputActive(), SDL_ClearComposition(), and SDL_SetTextInputRect() all now take a window parameter.

This change also fixes IME candidate positioning when SDL_SetTextInputRect() is called before SDL_StartTextInput(), as is recommended in the documentation.

Apologies if I've posted this in the wrong place.
I don't know the correct way to get the window pointer but below is my best attempt which seems to have got me up and running in Linux.

static void ImGui_ImplSDL3_SetPlatformImeData(ImGuiViewport* viewport, ImGuiPlatformImeData* data)
{
    SDL_Window * p_window = (SDL_Window *)viewport->PlatformHandle;
    if (data->WantVisible)
    {
        SDL_Rect r;
        r.x = (int)(data->InputPos.x - viewport->Pos.x);
        r.y = (int)(data->InputPos.y - viewport->Pos.y + data->InputLineHeight);
        r.w = 1;
        r.h = (int)data->InputLineHeight;
        SDL_SetTextInputRect(p_window, &r);
        SDL_StartTextInput(p_window);
    }
    else
    {
        SDL_StopTextInput(p_window);
    }
}

Screenshots/Video:

No response

Minimal, Complete and Verifiable Example code:

#include <imgui_impl_sdl3.h>

[zmertens]

I followed your replacement code but used SDL_Window * p_window = (SDL_Window *)viewport->PlatformHandleRaw;, note the Raw addition to the code, and it compiled the SDL3 imgui example. I am running on Ubuntu 24.

[ocornut]

Fixed with 7c24769. Note some logic changes required to handle change of windows.
It required adding viewport->PlatformHandle to master.
using PlatformHandleRaw is incorrect, it would be e.g. a HWND on Windows.

I will merge into docking soon.