How to open dialog box without ImGui::Button

[traw]

I am trying to open dialog box on pressing ImGui::MenuItem or by simple bool variable, but it doesn't work.

// Inside a ImGui window:
const bool browseButtonPressed = ImGui::Button("...");                          // we need a trigger boolean variable
static ImGuiFs::Dialog dlg;                                                     // one per dialog (and must be static)
const char* chosenPath = dlg.chooseFileDialog(browseButtonPressed);             // see other dialog types and the full list of arguments for advanced usage
if (strlen(chosenPath)>0) {
    // A path (chosenPath) has been chosen RIGHT NOW. However we can retrieve it later more comfortably using: dlg.getChosenPath()
}
if (strlen(dlg.getChosenPath())>0) {
    ImGui::Text("Chosen file: \"%s\"",dlg.getChosenPath());
}

// If you want to copy the (valid) returned path somewhere, you can use something like:
static char myPath[ImGuiFs::MAX_PATH_BYTES];
if (strlen(dlg.getChosenPath())>0) {
    strcpy(myPath,dlg.getChosenPath());
}

[Flix01]

Well, as far as I can see, you have just copied what's written at the top of imguifilesystem.h, and you haven't explained the problem you've experiencing (you're just saying: it doesn't work). Your post is not very useful 😢 .

Anyway:

• Have you tried to compile the first demo (examples/addon_examples/main.cpp) ? Does it work? It contains the following code:

        const char* startingFolder = "./";
        const char* optionalFileExtensionFilterString = "";//".jpg;.jpeg;.png;.tiff;.bmp;.gif;.txt";

        //------------------------------------------------------------------------------------------
        // 1 - ChooseFileDialogButton setup:
        //------------------------------------------------------------------------------------------
        ImGui::Text("Please choose a file: ");ImGui::SameLine();
        const bool browseButtonPressed = ImGui::Button("...");
        static ImGuiFs::Dialog fsInstance;
        const char* chosenPath = fsInstance.chooseFileDialog(browseButtonPressed,startingFolder,optionalFileExtensionFilterString);
        if (strlen(chosenPath)>0) {
            // A path (chosenPath) has been chosen right now. However we can retrieve it later using: fsInstance.getChosenPath()
        }
        if (strlen(fsInstance.getChosenPath())>0) ImGui::Text("Chosen path: \"%s\"",fsInstance.getChosenPath());

One thing that is worth noting is that the line with: fsInstance.chooseFileDialog(...) must be executed on every frame (modal dialogs in imgui can't just stop the main loop and wait for user selection).

• Are you using some particular character encoding (like simplified chinese) ?
  There might be additional problems with it (see: A better way to implement IMGUI::filesystem. #13)

[traw]

Yes I just copied the same code, It works fine when There is ImGui::Button("...");, but when I modify code like following it doesn't work. You can note the usage of showDialog in line 1, 4 and 22.

if(showDialog)
    {
// Inside a ImGui window:
        const bool browseButtonPressed = showDialog;                          // we need a trigger boolean variable
        static ImGuiFs::Dialog dlg;                                                     // one per dialog (and must be static)
        const char* chosenPath = dlg.chooseFileDialog(browseButtonPressed);             // see other dialog types and the full list of arguments for advanced usage
        if (strlen(chosenPath)>0)
        {
            // A path (chosenPath) has been chosen RIGHT NOW. However we can retrieve it later more comfortably using: dlg.getChosenPath()
        }
        if (strlen(dlg.getChosenPath())>0)
        {
            ImGui::Text("Chosen file: \"%s\"",dlg.getChosenPath());
        }

// If you want to copy the (valid) returned path somewhere, you can use something like:
        static char myPath[ImGuiFs::MAX_PATH_BYTES];
        if (strlen(dlg.getChosenPath())>0)
        {
            strcpy(myPath,dlg.getChosenPath());
        }
        showDialog = false;
    }

[Flix01]

While it's not clear to me what showDialog is, browseButtonPressed must be true only in a single frame, while dlg.chooseFileDialog(browseButtonPressed); must be called always (every frame). So if showDialog is set so that it's correctly true only in a single frame, you should try removing the if statement at line 1, so that dlg.chooseFileDialog(browseButtonPressed); is always called.
Maybe something like:

        static ImGuiFs::Dialog dlg;                                                     // one per dialog (and must be static)
        const char* chosenPath = dlg.chooseFileDialog(showDialog);             // see other dialog types and the full list of arguments for advanced usage
        if (strlen(chosenPath)>0)
        {
            // A path (chosenPath) has been chosen RIGHT NOW. However we can retrieve it later more comfortably using: dlg.getChosenPath()
        }
        if (strlen(dlg.getChosenPath())>0)
        {
            ImGui::Text("Chosen file: \"%s\"",dlg.getChosenPath());
        }
    if (showDialog) showDialog=false;

[traw]

Thanks it' working now. With changes you suggested. Just little doubt why static ImGuiFs::Dialog dlg; need to static?

Note for Future reference:

browseButtonPressed must be true only in a single frame, while dlg.chooseFileDialog(browseButtonPressed); must be called always (every frame).

[Flix01]

why static ImGuiFs::Dialog dlg; need to static?

Well, it can't be a local variable, because it keeps a lot of state variables inside (for example the navigation history while the dialog is open). [Obviously, it can be a global variable too].

browseButtonPressed must be true only in a single frame, while dlg.chooseFileDialog(browseButtonPressed); must be called always (every frame).

Yes. One thing that is worth noting is that the line with: fsInstance.chooseFileDialog(...) must be executed on every frame (modal dialogs in imgui can't just stop the main loop and wait for user selection).

[tolstenko]

Hello there, I have similar question here. Could you kindly provide me an example using chooseFileDialog inside BeginMenu as menuitem, instead of a button?

Here is my ugly solution, it works, but the selection area is smaller than the others MenuItems:

if (ImGui::BeginMenu("File"))
  {
    ImGui::PushStyleColor(ImGuiCol_Button,ImVec4(0,0,0,0));
    const bool browseButtonPressed = ImGui::Button("Open...");
    static ImGuiFs::Dialog dlg;
    const char* chosenPath = dlg.chooseFileDialog(browseButtonPressed, nullptr, nullptr);
    ImGui::PopStyleColor(1);
    ImGui::EndMenu();
}

[Flix01]

I'd do something like:

        bool browseButtonPressed = false;
        if (ImGui::BeginMenu("File"))   {
            browseButtonPressed = ImGui::MenuItem("Open...", "CTRL+O");
            ImGui::EndMenu();
        }
        static ImGuiFs::Dialog dlg;
        const char* chosenPath = dlg.chooseFileDialog(browseButtonPressed);

Does it work better or not ?

[tolstenko]

That's awesome! Thank you!