Added AddDockableWindow() / RemoveDockableWindow()

src/hello_imgui/doc_api.md

@@ -324,6 +324,14 @@ void           SwitchLayout(const std::string& layoutName);
 
 // `CurrentLayoutName()`: returns the name of the current layout
 std::string    CurrentLayoutName();
+
+// `AddDockableWindow()`: will add a dockable window to the current layout.
+// Will dock the window to the dockspace it belongs to.
+void AddDockableWindow(const DockableWindow& dockableWindow);
+
+// `RemoveDockableWindow()`: will remove a dockable window from the current layout.
+void RemoveDockableWindow(const std::string& dockableWindowName);
+
 ```
 
 ----

src/hello_imgui/doc_params.md

@@ -1163,7 +1163,7 @@ struct DockableWindow
 {
     // --------------- Main params -------------------
 
-    // `label`: _string_. Title of the window.
+    // `label`: _string_. Title of the window. It should be unique! Use "##" to add a unique suffix if needed.
     std::string label;
 
     // `dockSpaceName`: _DockSpaceName (aka string)_.

src/hello_imgui/docking_params.h

@@ -210,7 +210,7 @@ struct DockableWindow
 {
     // --------------- Main params -------------------
 
-    // `label`: _string_. Title of the window.
+    // `label`: _string_. Title of the window. It should be unique! Use "##" to add a unique suffix if needed.
     std::string label;
 
     // `dockSpaceName`: _DockSpaceName (aka string)_.

src/hello_imgui/hello_imgui.h

@@ -138,6 +138,14 @@ void           SwitchLayout(const std::string& layoutName);
 
 // `CurrentLayoutName()`: returns the name of the current layout
 std::string    CurrentLayoutName();
+
+// `AddDockableWindow()`: will add a dockable window to the current layout.
+// Will dock the window to the dockspace it belongs to.
+void AddDockableWindow(const DockableWindow& dockableWindow);
+
+// `RemoveDockableWindow()`: will remove a dockable window from the current layout.
+void RemoveDockableWindow(const std::string& dockableWindowName);
+
 // @@md
 
 

src/hello_imgui/internal/backend_impls/abstract_runner.cpp

@@ -86,6 +86,14 @@ bool ShouldRemoteDisplay();
 // Encapsulated inside docking_details.cpp
 void ShowThemeTweakGuiWindow_Static();
 
+// Encapsulated inside docking_details.cpp
+namespace AddDockableWindowHelper
+{
+    void Callback_1_GuiRender();
+    void Callback_2_PreNewFrame();
+}
+
+
 
 struct AbstractRunnerStatics
 {
@@ -1323,6 +1331,10 @@ void AbstractRunner::CreateFramesAndRender(bool insideReentrantCall)
         fnLoadAdditionalFontDuringExecution_UserCallback(); // User callback
     }
 
+    // Handle AddDockableWindow(): this call should be done before ImGui::NewFrame
+    if (!insideReentrantCall)
+        AddDockableWindowHelper::Callback_2_PreNewFrame();
+
     if ((params.callbacks.PreNewFrame) && !insideReentrantCall)
         params.callbacks.PreNewFrame();
 
@@ -1341,6 +1353,9 @@ void AbstractRunner::CreateFramesAndRender(bool insideReentrantCall)
         fnDrawCustomBackgroundOrClearColor_UserCallback(); // User callback
     }
 
+    // Handle AddDockableWindow(): this call should be done when ImGui is accepting widgets
+    AddDockableWindowHelper::Callback_1_GuiRender();
+
     // iii/ At the end of the second frame, we measure the size of the widgets and use it as the application window size,
     // if the user required auto size
     // ==> Note: RenderGui() may measure the size of the window and resize it if mIdxFrame==1

src/hello_imgui/internal/docking_details.cpp

@@ -7,6 +7,7 @@
 #include "hello_imgui/internal/functional_utils.h"
 #include "imgui_internal.h"
 #include <map>
+#include <vector>
 #include <cassert>
 #include <optional>
 
@@ -608,4 +609,102 @@ std::optional<ImGuiID> DockingParams::dockSpaceIdFromName(const std::string& doc
 }
 
 
+// `AddDockableWindow()` implementation and helper
+namespace AddDockableWindowHelper
+{
+    // Adding dockable windows is a three-step process:
+    // - First, the user calls `AddDockableWindow()`: the dockable window is added to gDockableWindowsToAdd
+    //   with the state `DockableWindowAdditionState::Waiting`
+    // - Then, in the first callback, the dockable window is added to ImGui as a dummy window:
+    //   we call `ImGui::Begin()` and `ImGui::End()` to create the window, but we don't draw anything in it,
+    //   then we call `ImGui::DockBuilderDockWindow()` to dock the window to the correct dockspace
+    // - Finally, in the second callback, the dockable window is added to HelloImGui::RunnerParams.dockingParams.dockableWindows
+
+    enum class DockableWindowAdditionState
+    {
+        Waiting,
+        AddedAsDummyToImGui,
+        AddedToHelloImGui
+    };
+
+    struct DockableWindowWaitingForAddition
+    {
+        DockableWindow dockableWindow;
+        DockableWindowAdditionState state = DockableWindowAdditionState::Waiting;
+    };
+
+    std::vector<DockableWindowWaitingForAddition> gDockableWindowsToAdd;
+
+    void AddDockableWindow(const DockableWindow& dockableWindow)
+    {
+        gDockableWindowsToAdd.push_back({dockableWindow, DockableWindowAdditionState::Waiting});
+    }
+
+    void Callback_1_GuiRender()
+    {
+        for (auto & dockableWindow: gDockableWindowsToAdd)
+        {
+            if (dockableWindow.state == DockableWindowAdditionState::Waiting)
+            {
+                ImGui::Begin(dockableWindow.dockableWindow.label.c_str());
+                ImGui::Dummy(ImVec2(10, 10));
+                ImGui::End();
+
+                auto dockId = HelloImGui::GetRunnerParams()->dockingParams.dockSpaceIdFromName(dockableWindow.dockableWindow.dockSpaceName);
+                if (dockId.has_value())
+                    ImGui::DockBuilderDockWindow(dockableWindow.dockableWindow.label.c_str(), dockId.value());
+
+                dockableWindow.state = DockableWindowAdditionState::AddedAsDummyToImGui;
+            }
+        }
+    }
+
+    void Callback_2_PreNewFrame()
+    {
+        for (auto & dockableWindow: gDockableWindowsToAdd)
+        {
+            if (dockableWindow.state == DockableWindowAdditionState::AddedAsDummyToImGui)
+            {
+                HelloImGui::GetRunnerParams()->dockingParams.dockableWindows.push_back(dockableWindow.dockableWindow);
+                dockableWindow.state = DockableWindowAdditionState::AddedToHelloImGui;
+            }
+        }
+
+        // Remove the dockable windows that have been added to HelloImGui
+        gDockableWindowsToAdd.erase(  // typical C++ shenanigans
+            std::remove_if(
+                gDockableWindowsToAdd.begin(),
+                gDockableWindowsToAdd.end(),
+                [](const DockableWindowWaitingForAddition& dockableWindow) {
+                    return dockableWindow.state == DockableWindowAdditionState::AddedToHelloImGui;
+                }
+            ),
+            gDockableWindowsToAdd.end()
+        );
+    }
+
+} // namespace AddDockableWindowHelper
+
+
+void AddDockableWindow(const DockableWindow& dockableWindow)
+{
+    AddDockableWindowHelper::AddDockableWindow(dockableWindow);
+}
+
+void RemoveDockableWindow(const std::string& dockableWindowName)
+{
+    auto& dockableWindows = HelloImGui::GetRunnerParams()->dockingParams.dockableWindows;
+    dockableWindows.erase(
+        std::remove_if(
+            dockableWindows.begin(),
+            dockableWindows.end(),
+            [&dockableWindowName](const DockableWindow& dockableWindow) {
+                return dockableWindow.label == dockableWindowName;
+            }
+        ),
+        dockableWindows.end()
+    );
+}
+
+
 }  // namespace HelloImGui

src/hello_imgui_demos/hello_imgui_demodocking/hello_imgui_demodocking.main.cpp

@@ -178,26 +178,27 @@ void DemoHideWindow(AppState& appState)
     }
 }
 
-// Display a button that will show an additional window
+// Display a button that will add another dockable window during execution
 void DemoShowAdditionalWindow(AppState& appState)
 {
-    // Notes:
-    //     - it is *not* possible to modify the content of the vector runnerParams.dockingParams.dockableWindows
-    //       from the code inside a window's `GuiFunction` (since this GuiFunction will be called while iterating on this vector!)
-    //     - there are two ways to dynamically add windows:
-    //           * either make them initially invisible, and exclude them from the view menu (such as shown here)
-    //           * or modify runnerParams.dockingParams.dockableWindows inside the callback RunnerCallbacks.PreNewFrame
+    // In order to add a dockable window during execution, you should use
+    //     HelloImGui::AddDockableWindow()
+
+    // Note: you should not modify manually the content of the vector runnerParams.dockingParams.dockableWindows
+    //       (since HelloImGui is constantly looping on it)
     const char* windowName = "Additional Window";
     ImGui::PushFont(appState.TitleFont->font); ImGui::Text("Dynamically add window"); ImGui::PopFont();
     if (ImGui::Button("Show additional window"))
     {
-        auto additionalWindowPtr = HelloImGui::GetRunnerParams()->dockingParams.dockableWindowOfName(windowName);
-        if (additionalWindowPtr)
-        {
-            // additionalWindowPtr->includeInViewMenu = true;
-            additionalWindowPtr->isVisible = true;
-        }
+        HelloImGui::DockableWindow additionalWindow;
+        additionalWindow.label = "Additional Window";
+        additionalWindow.includeInViewMenu = false;       // this window is not shown in the view menu,
+        additionalWindow.rememberIsVisible = false;       // its visibility is not saved in the settings file,
+        additionalWindow.dockSpaceName = "MiscSpace";     // when shown, it will appear in MiscSpace.
+        additionalWindow.GuiFunction = [] { ImGui::Text("This is the additional window"); };
+        HelloImGui::AddDockableWindow(additionalWindow);
     }
+
     if (ImGui::IsItemHovered())
         ImGui::SetTooltip("By clicking this button, you can show an additional window");
 }
@@ -729,16 +730,6 @@ std::vector<HelloImGui::DockableWindow> CreateDockableWindows(AppState& appState
     dearImGuiDemoWindow.imGuiWindowFlags = ImGuiWindowFlags_MenuBar;
     dearImGuiDemoWindow.GuiFunction = [] { ImGui::ShowDemoWindow(); };
 
-    // additionalWindow is initially not visible (and not mentioned in the view menu).
-    // it will be opened only if the user chooses to display it
-    HelloImGui::DockableWindow additionalWindow;
-    additionalWindow.label = "Additional Window";
-    additionalWindow.isVisible = false;               // this window is initially hidden,
-    additionalWindow.includeInViewMenu = false;       // it is not shown in the view menu,
-    additionalWindow.rememberIsVisible = false;       // its visibility is not saved in the settings file,
-    additionalWindow.dockSpaceName = "MiscSpace";     // when shown, it will appear in BottomSpace.
-    additionalWindow.GuiFunction = [] { ImGui::Text("This is the additional window"); };
-
     // alternativeThemeWindow
     HelloImGui::DockableWindow alternativeThemeWindow;
     // Since this window applies a theme, We need to call "ImGui::Begin" ourselves so
@@ -753,7 +744,6 @@ std::vector<HelloImGui::DockableWindow> CreateDockableWindows(AppState& appState
         layoutCustomizationWindow,
         logsWindow,
         dearImGuiDemoWindow,
-        additionalWindow,
         alternativeThemeWindow
     };
     return dockableWindows;