Movable / Resizable borderless windows (Merge branch 'borderless_resi…

…zable2')

src/hello_imgui/app_window_params.h

@@ -164,18 +164,28 @@ for details.
    _Note: on a mobile device, the application will always be full screen._
 * `restorePreviousGeometry`: _bool, default=false_.
   If true, then save & restore windowGeometry from last run (the geometry will be written in imgui_app_window.ini)
-* `borderless`: _bool, default = false_. Should the window have borders. This is taken into account at
-creation.
-* `resizable`: _bool, default = false_. Should the window have borders. This is taken into account at
-creation.
+* `resizable`: _bool, default = false_. Should the window be resizable. This is taken into account at
+  creation.
 * `hidden`: _bool, default = false_. Should the window be hidden. This is taken into account dynamically (you
-can show/hide the window with this). Full screen windows cannot be hidden.@@md
+  can show/hide the window with this). Full screen windows cannot be hidden.
+
+* `borderless`: _bool, default = false_. Should the window have borders. This is taken into account at creation.
+* `borderlessMovable`: _bool, default = true_. If the window is borderless, should it be movable.
+   If so, a drag zone is displayed at the top of the window when the mouse is over it.
+* `borderlessResizable`: _bool, default = true_. If the window is borderless, should it be resizable.
+   If so, a drag zone is displayed at the bottom-right of the window when the mouse is over it.
+* `borderlessHighlightColor`: _ImVec4, default = ImVec4(0.2f, 0.4f, 1.f, 0.f)_.
+   Color of the highlight displayed on resize/move zones. If borderlessHighlightColor.w==0,
+   then the highlightColor will be automatically set to ImGui::GetColorU32(ImGuiCol_TitleBgActive, 0.6f)
+
 * `edgeInsets`: _EdgeInsets_. iOS only, out values filled by HelloImGui:
   if there is a notch on the iPhone, you should not display inside these insets.
   HelloImGui handles this automatically, if handleEdgeInsets is true and
   if runnerParams.imGuiWindowParams.defaultImGuiWindowType is not NoDefaultWindow.
   (warning, these values are updated only after a few frames, they are typically 0 for the first 4 frames)
 * `handleEdgeInsets`: _bool, default = true_. iOS only, if true, HelloImGui will handle the edgeInsets.
+
+@@md
 **/
 struct AppWindowParams
 {
@@ -186,10 +196,14 @@ struct AppWindowParams
     // if true, then save & restore from last run
     bool restorePreviousGeometry = false;
 
-    bool borderless = false;
     bool resizable = true;
     bool hidden = false;
 
+    bool   borderless = false;
+    bool   borderlessMovable = true;
+    bool   borderlessResizable = true;
+    ImVec4 borderlessHighlightColor = ImVec4(0.2f, 0.4f, 1.f, 0.3f);
+
     EdgeInsets edgeInsets;
     bool       handleEdgeInsets = true;
 };

src/hello_imgui/internal/backend_impls/abstract_runner.cpp

@@ -1,9 +1,10 @@
 #include "hello_imgui/internal/backend_impls/abstract_runner.h"
-#include "hello_imgui/internal/hello_imgui_ini_settings.h"
-#include "hello_imgui/internal/docking_details.h"
-#include "hello_imgui/internal/menu_statusbar.h"
 #include "hello_imgui/hello_imgui_theme.h"
+#include "hello_imgui/internal/borderless_movable.h"
 #include "hello_imgui/internal/clock_seconds.h"
+#include "hello_imgui/internal/docking_details.h"
+#include "hello_imgui/internal/hello_imgui_ini_settings.h"
+#include "hello_imgui/internal/menu_statusbar.h"
 #include "hello_imgui/internal/platform/ini_folder_locations.h"
 #include "imgui.h"
 
@@ -504,6 +505,13 @@ void AbstractRunner::RenderGui()
     if (params.imGuiWindowParams.showMenuBar)
         Menu_StatusBar::ShowMenu(params);
 
+    if (params.appWindowParams.borderless) // Need to add params.appWindowParams.borderlessResizable
+        HandleBorderlessMovable(mWindow,
+                                mBackendWindowHelper.get(),
+                                params.appWindowParams.borderlessMovable,
+                                params.appWindowParams.borderlessResizable,
+                                params.appWindowParams.borderlessHighlightColor);
+
     if (params.callbacks.ShowGui)
     {
         bool wantAutoSize = WantAutoSize();

src/hello_imgui/internal/backend_impls/backend_window_helper/glfw_window_helper.cpp

@@ -216,5 +216,11 @@ namespace HelloImGui { namespace BackendApi
         return (visible == 0);
     }
 
+//    void truc(WindowPointer window)
+//    {
+//        glfwCur
+//
+//    }
+
 }} // namespace HelloImGui { namespace BackendApi
 #endif // #ifdef HELLOIMGUI_USE_GLFW

src/hello_imgui/internal/borderless_movable.cpp

@@ -0,0 +1,110 @@
+#define IMGUI_DEFINE_MATH_OPERATORS
+#include "hello_imgui/internal/borderless_movable.h"
+#include "hello_imgui/hello_imgui.h"
+#include "imgui_internal.h"
+
+
+namespace HelloImGui
+{
+    void HandleBorderlessMovable(
+        BackendApi::WindowPointer window,
+        BackendApi::IBackendWindowHelper * backendWindowHelper,
+        bool borderlessMovable,
+        bool borderlessResizable,
+        ImVec4 borderlessHighlightColor)
+    {
+        ImU32 highlightColorU32 = ImGui::GetColorU32(borderlessHighlightColor);
+        if (borderlessHighlightColor.w == 0.f)
+            highlightColorU32 = ImGui::GetColorU32(ImGuiCol_TitleBg, 0.6f);
+
+        // Drag zone at the top of the window
+        if (borderlessMovable)
+        {
+            ImVec2 dragSize(ImGui::GetMainViewport()->Size.x, ImGui::GetFontSize() * 1.5f);
+            ImRect dragArea(ImGui::GetMainViewport()->Pos, ImGui::GetMainViewport()->Pos + dragSize);
+
+            // Update dragging state
+            ImVec2 mousePos = ImGui::GetMousePos();
+            static bool isDragging = false;
+            if (dragArea.Contains(mousePos) && !isDragging && ImGui::IsMouseDown(ImGuiMouseButton_Left))
+            {
+                isDragging = true;
+            }
+            if (!ImGui::IsMouseDown(ImGuiMouseButton_Left) && isDragging)
+                isDragging = false;
+
+            // Draw drag zone
+            if (dragArea.Contains(mousePos) || isDragging)
+            {
+                ImGui::GetForegroundDrawList()->AddRectFilled(
+                    dragArea.Min,
+                    dragArea.Max,
+                    highlightColorU32
+                );
+            }
+
+            // Move window if dragging
+            if (isDragging)
+            {
+                ImVec2 dragDelta = ImGui::GetMouseDragDelta(0);
+                ImGui::ResetMouseDragDelta(0);
+                auto windowBounds = backendWindowHelper->GetWindowBounds(window);
+                windowBounds.position[0] += (int)dragDelta.x;
+                windowBounds.position[1] += (int)dragDelta.y;
+                backendWindowHelper->SetWindowBounds(window, windowBounds);
+                ImGui::ResetMouseDragDelta(ImGuiMouseButton_Left);
+            }
+
+            // Set mouse cursor: probably not visible for moving (the cursor will be the classic arrow)
+            if (dragArea.Contains(mousePos) || isDragging)
+                ImGui::SetMouseCursor(ImGuiMouseCursor_Arrow);
+        }
+
+        // Drag zone at the bottom-right of the window
+        if (borderlessResizable)
+        {
+            ImVec2 bottomRightCorner = ImGui::GetMainViewport()->Pos + ImGui::GetMainViewport()->Size;
+            ImVec2 topLeftCorner = bottomRightCorner - HelloImGui::EmToVec2(1.5f, 1.5f);
+            ImRect dragArea = ImRect(topLeftCorner, bottomRightCorner);
+
+            // Update dragging state
+            static bool isDragging = false;
+            ImVec2 mousePos = ImGui::GetIO().MousePos;
+            if (dragArea.Contains(mousePos) && !isDragging && ImGui::IsMouseDown(ImGuiMouseButton_Left))
+                isDragging = true;
+            if (!ImGui::IsMouseDown(ImGuiMouseButton_Left))
+                isDragging = false;
+
+            // Draw drag zone
+            if (dragArea.Contains(mousePos) || isDragging)
+            {
+                // Small triangle in the bottom-right corner
+                ImVec2 t1 = bottomRightCorner;
+                ImVec2 t2 = bottomRightCorner - HelloImGui::EmToVec2(1.5f, 0.f);
+                ImVec2 t3 = bottomRightCorner - HelloImGui::EmToVec2(0.f, 1.5f);
+                ImGui::GetForegroundDrawList()->AddTriangleFilled(
+                    t1, t2, t3,
+                    highlightColorU32
+                );
+            }
+
+            // Resize window if dragging
+            if (isDragging)
+            {
+                ImVec2 dragDelta = ImGui::GetMouseDragDelta(0);
+                ImGui::ResetMouseDragDelta(0);
+                auto windowBounds = backendWindowHelper->GetWindowBounds(window);
+                windowBounds.size[0] += (int)dragDelta.x;
+                windowBounds.size[1] += (int)dragDelta.y;
+                backendWindowHelper->SetWindowBounds(window, windowBounds);
+                ImGui::ResetMouseDragDelta(ImGuiMouseButton_Left);
+            }
+
+            // Set mouse cursor: (not visible under glfw < 3.4, which does not implement this cursor)
+            if (dragArea.Contains(mousePos) || isDragging)
+                ImGui::SetMouseCursor(ImGuiMouseCursor_ResizeNWSE);
+        }
+    }
+}
+
+

src/hello_imgui/internal/borderless_movable.h

@@ -0,0 +1,14 @@
+#pragma once
+#include "hello_imgui/runner_params.h"
+#include "hello_imgui/internal/backend_impls/backend_window_helper/backend_window_helper.h"
+
+namespace HelloImGui
+{
+    void HandleBorderlessMovable(
+        BackendApi::WindowPointer window,
+        BackendApi::IBackendWindowHelper * backendWindowHelper,
+        bool borderlessMovable,
+        bool borderlessResizable,
+        ImVec4 borderlessHighlightColor
+    );
+}

src/hello_imgui_demos/hello_imgui_demodocking/hello_imgui_demodocking.main.cpp

@@ -498,6 +498,11 @@ int main(int, char**)
     runnerParams.imGuiWindowParams.menuAppTitle = "Docking Demo";
     runnerParams.appWindowParams.windowGeometry.size = {1000, 900};
     runnerParams.appWindowParams.restorePreviousGeometry = true;
+
+    // Our application uses a borderless window, but is movable/resizable
+    runnerParams.appWindowParams.borderless = true;
+    runnerParams.appWindowParams.borderlessMovable = true;
+    runnerParams.appWindowParams.borderlessResizable = true;
 
     // Load additional font
     runnerParams.callbacks.LoadAdditionalFonts = LoadFonts;