Merge branch 'master' into docking + dockspace demo comments

# Conflicts:
#	backends/imgui_impl_opengl3.cpp
#	docs/CHANGELOG.txt
#	imgui_internal.h
#	imgui_widgets.cpp

backends/imgui_impl_opengl3.cpp

@@ -15,6 +15,7 @@
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
 //  2020-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
+//  2020-10-15: OpenGL: Use glGetString(GL_VERSION) instead of glGetIntegerv(GL_MAJOR_VERSION, ...) when the later returns zero (e.g. Desktop GL 2.x)
 //  2020-09-17: OpenGL: Fix to avoid compiling/calling glBindSampler() on ES or pre 3.3 context which have the defines set by a loader.
 //  2020-07-10: OpenGL: Added support for glad2 OpenGL loader.
 //  2020-05-08: OpenGL: Made default GLSL version 150 (instead of 130) on OSX.
@@ -153,9 +154,16 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
 {
     // Query for GL version (e.g. 320 for GL 3.2)
 #if !defined(IMGUI_IMPL_OPENGL_ES2)
-    GLint major, minor;
+    GLint major = 0;
+    GLint minor = 0;
     glGetIntegerv(GL_MAJOR_VERSION, &major);
     glGetIntegerv(GL_MINOR_VERSION, &minor);
+    if (major == 0 && minor == 0)
+    {
+        // Query GL_VERSION in desktop GL 2.x, the string will start with "<major>.<minor>"
+        const char* gl_version = (const char*)glGetString(GL_VERSION);
+        sscanf(gl_version, "%d.%d", &major, &minor);
+    }
     g_GlVersion = (GLuint)(major * 100 + minor * 10);
 #else
     g_GlVersion = 200; // GLES 2

docs/CHANGELOG.txt

@@ -123,6 +123,12 @@ Breaking Changes:
 Other Changes:
 
 - Tab Bar: Made it possible to append to an existing tab bar by calling BeginTabBar()/EndTabBar() again.
+- Tab Bar: Fixed using more than 128 tabs in a tab bar (scrolling policy recommended).
+- Tab Bar: Do not display a tooltip if the name already fits over a given tab. (#3521)
+- Drag and Drop: Fix drag and drop to tie same-size drop targets by choosen the later one. Fixes dragging
+  into a full-window-sized dockspace inside a zero-padded window. (#3519, #2717) [@Black-Cat]
+- Backends: OpenGL: use glGetString(GL_VERSION) query instead of glGetIntegerv(GL_MAJOR_VERSION, ...) 
+  when the later returns zero (e.g. Desktop GL 2.x). (#3530) [@xndcn]
 - Docs: Split examples/README.txt into docs/BACKENDS.md and docs/EXAMPLES.md improved them.
 - Docs: Consistently renamed all occurences of "binding" and "back-end" to "backend" in comments and docs.
 

imgui.cpp

@@ -10335,7 +10335,7 @@ const ImGuiPayload* ImGui::AcceptDragDropPayload(const char* type, ImGuiDragDrop
     const bool was_accepted_previously = (g.DragDropAcceptIdPrev == g.DragDropTargetId);
     ImRect r = g.DragDropTargetRect;
     float r_surface = r.GetWidth() * r.GetHeight();
-    if (r_surface < g.DragDropAcceptIdCurrRectSurface)
+    if (r_surface <= g.DragDropAcceptIdCurrRectSurface)
     {
         g.DragDropAcceptFlags = flags;
         g.DragDropAcceptIdCurr = g.DragDropTargetId;
@@ -13847,7 +13847,7 @@ static void ImGui::DockNodePreviewDockRender(ImGuiWindow* host_window, ImGuiDock
                 if (!tab_bar_rect.Contains(tab_bb))
                     overlay_draw_lists[overlay_n]->PushClipRect(tab_bar_rect.Min, tab_bar_rect.Max);
                 TabItemBackground(overlay_draw_lists[overlay_n], tab_bb, tab_flags, overlay_col_tabs);
-                TabItemLabelAndCloseButton(overlay_draw_lists[overlay_n], tab_bb, tab_flags, g.Style.FramePadding, payload_window->Name, 0, 0, false);
+                TabItemLabelAndCloseButton(overlay_draw_lists[overlay_n], tab_bb, tab_flags, g.Style.FramePadding, payload_window->Name, 0, 0, false, NULL, NULL);
                 if (!tab_bar_rect.Contains(tab_bb))
                     overlay_draw_lists[overlay_n]->PopClipRect();
             }

imgui.h

@@ -534,14 +534,14 @@ namespace ImGui
     IMGUI_API bool          InputScalar(const char* label, ImGuiDataType data_type, void* p_data, const void* p_step = NULL, const void* p_step_fast = NULL, const char* format = NULL, ImGuiInputTextFlags flags = 0);
     IMGUI_API bool          InputScalarN(const char* label, ImGuiDataType data_type, void* p_data, int components, const void* p_step = NULL, const void* p_step_fast = NULL, const char* format = NULL, ImGuiInputTextFlags flags = 0);
 
-    // Widgets: Color Editor/Picker (tip: the ColorEdit* functions have a little colored preview square that can be left-clicked to open a picker, and right-clicked to open an option menu.)
+    // Widgets: Color Editor/Picker (tip: the ColorEdit* functions have a little color square that can be left-clicked to open a picker, and right-clicked to open an option menu.)
     // - Note that in C++ a 'float v[X]' function argument is the _same_ as 'float* v', the array syntax is just a way to document the number of elements that are expected to be accessible.
     // - You can pass the address of a first float element out of a contiguous structure, e.g. &myvector.x
     IMGUI_API bool          ColorEdit3(const char* label, float col[3], ImGuiColorEditFlags flags = 0);
     IMGUI_API bool          ColorEdit4(const char* label, float col[4], ImGuiColorEditFlags flags = 0);
     IMGUI_API bool          ColorPicker3(const char* label, float col[3], ImGuiColorEditFlags flags = 0);
     IMGUI_API bool          ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags flags = 0, const float* ref_col = NULL);
-    IMGUI_API bool          ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFlags flags = 0, ImVec2 size = ImVec2(0, 0)); // display a colored square/button, hover for details, return true when pressed.
+    IMGUI_API bool          ColorButton(const char* desc_id, const ImVec4& col, ImGuiColorEditFlags flags = 0, ImVec2 size = ImVec2(0, 0)); // display a color square/button, hover for details, return true when pressed.
     IMGUI_API void          SetColorEditOptions(ImGuiColorEditFlags flags);                     // initialize current options (generally on application startup) if you want to select a default format, picker type, etc. User will be able to change many settings, unless you pass the _NoOptions flag to your calls.
 
     // Widgets: Trees
@@ -909,7 +909,7 @@ enum ImGuiTreeNodeFlags_
 {
     ImGuiTreeNodeFlags_None                 = 0,
     ImGuiTreeNodeFlags_Selected             = 1 << 0,   // Draw as selected
-    ImGuiTreeNodeFlags_Framed               = 1 << 1,   // Full colored frame (e.g. for CollapsingHeader)
+    ImGuiTreeNodeFlags_Framed               = 1 << 1,   // Draw frame with background (e.g. for CollapsingHeader)
     ImGuiTreeNodeFlags_AllowItemOverlap     = 1 << 2,   // Hit testing to allow subsequent widgets to overlap this one
     ImGuiTreeNodeFlags_NoTreePushOnOpen     = 1 << 3,   // Don't do a TreePush() when open (e.g. for CollapsingHeader) = no extra indent nor pushing on ID stack
     ImGuiTreeNodeFlags_NoAutoOpenOnLog      = 1 << 4,   // Don't automatically and temporarily open node when Logging is active (by default logging will automatically open tree nodes)
@@ -1324,13 +1324,13 @@ enum ImGuiColorEditFlags_
 {
     ImGuiColorEditFlags_None            = 0,
     ImGuiColorEditFlags_NoAlpha         = 1 << 1,   //              // ColorEdit, ColorPicker, ColorButton: ignore Alpha component (will only read 3 components from the input pointer).
-    ImGuiColorEditFlags_NoPicker        = 1 << 2,   //              // ColorEdit: disable picker when clicking on colored square.
+    ImGuiColorEditFlags_NoPicker        = 1 << 2,   //              // ColorEdit: disable picker when clicking on color square.
     ImGuiColorEditFlags_NoOptions       = 1 << 3,   //              // ColorEdit: disable toggling options menu when right-clicking on inputs/small preview.
-    ImGuiColorEditFlags_NoSmallPreview  = 1 << 4,   //              // ColorEdit, ColorPicker: disable colored square preview next to the inputs. (e.g. to show only the inputs)
-    ImGuiColorEditFlags_NoInputs        = 1 << 5,   //              // ColorEdit, ColorPicker: disable inputs sliders/text widgets (e.g. to show only the small preview colored square).
+    ImGuiColorEditFlags_NoSmallPreview  = 1 << 4,   //              // ColorEdit, ColorPicker: disable color square preview next to the inputs. (e.g. to show only the inputs)
+    ImGuiColorEditFlags_NoInputs        = 1 << 5,   //              // ColorEdit, ColorPicker: disable inputs sliders/text widgets (e.g. to show only the small preview color square).
     ImGuiColorEditFlags_NoTooltip       = 1 << 6,   //              // ColorEdit, ColorPicker, ColorButton: disable tooltip when hovering the preview.
     ImGuiColorEditFlags_NoLabel         = 1 << 7,   //              // ColorEdit, ColorPicker: disable display of inline text label (the label is still forwarded to the tooltip and picker).
-    ImGuiColorEditFlags_NoSidePreview   = 1 << 8,   //              // ColorPicker: disable bigger color preview on right side of the picker, use small colored square preview instead.
+    ImGuiColorEditFlags_NoSidePreview   = 1 << 8,   //              // ColorPicker: disable bigger color preview on right side of the picker, use small color square preview instead.
     ImGuiColorEditFlags_NoDragDrop      = 1 << 9,   //              // ColorEdit: disable drag and drop target. ColorButton: disable drag and drop source.
     ImGuiColorEditFlags_NoBorder        = 1 << 10,  //              // ColorButton: disable border (which is enforced by default)
 

imgui_demo.cpp

@@ -708,9 +708,9 @@ static void ShowDemoWindowWidgets()
             static float col2[4] = { 0.4f, 0.7f, 0.0f, 0.5f };
             ImGui::ColorEdit3("color 1", col1);
             ImGui::SameLine(); HelpMarker(
-                "Click on the colored square to open a color picker.\n"
+                "Click on the color square to open a color picker.\n"
                 "Click and hold to use drag and drop.\n"
-                "Right-click on the colored square to show options.\n"
+                "Right-click on the color square to show options.\n"
                 "CTRL+click on individual component to input value.\n");
 
             ImGui::ColorEdit4("color 2", col2);
@@ -879,7 +879,7 @@ static void ShowDemoWindowWidgets()
 
     if (ImGui::TreeNode("Text"))
     {
-        if (ImGui::TreeNode("Colored Text"))
+        if (ImGui::TreeNode("Colorful Text"))
         {
             // Using shortcut. You can use PushStyleColor()/PopStyleColor() for more flexibility.
             ImGui::TextColored(ImVec4(1.0f, 0.0f, 1.0f, 1.0f), "Pink");
@@ -1461,7 +1461,7 @@ static void ShowDemoWindowWidgets()
 
         ImGui::Text("Color widget:");
         ImGui::SameLine(); HelpMarker(
-            "Click on the colored square to open a color picker.\n"
+            "Click on the color square to open a color picker.\n"
             "CTRL+click on individual component to input value.\n");
         ImGui::ColorEdit3("MyColor##1", (float*)&color, misc_flags);
 
@@ -1881,7 +1881,7 @@ static void ShowDemoWindowWidgets()
             // They are using standardized payload strings IMGUI_PAYLOAD_TYPE_COLOR_3F and IMGUI_PAYLOAD_TYPE_COLOR_4F
             // to allow your own widgets to use colors in their drag and drop interaction.
             // Also see 'Demo->Widgets->Color/Picker Widgets->Palette' demo.
-            HelpMarker("You can drag from the colored squares.");
+            HelpMarker("You can drag from the color squares.");
             static float col1[3] = { 1.0f, 0.0f, 0.2f };
             static float col2[4] = { 0.4f, 0.7f, 0.0f, 0.5f };
             ImGui::ColorEdit3("color 1", col1);
@@ -4059,7 +4059,7 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             if (ImGui::RadioButton("Both",   alpha_flags == ImGuiColorEditFlags_AlphaPreviewHalf)) { alpha_flags = ImGuiColorEditFlags_AlphaPreviewHalf; } ImGui::SameLine();
             HelpMarker(
                 "In the color list:\n"
-                "Left-click on colored square to open color picker,\n"
+                "Left-click on color square to open color picker,\n"
                 "Right-click to open edit options menu.");
 
             ImGui::BeginChild("##colors", ImVec2(0, 0), true, ImGuiWindowFlags_AlwaysVerticalScrollbar | ImGuiWindowFlags_AlwaysHorizontalScrollbar | ImGuiWindowFlags_NavFlattened);
@@ -5401,11 +5401,24 @@ static void ShowExampleAppCustomRendering(bool* p_open)
 //-----------------------------------------------------------------------------
 
 // Demonstrate using DockSpace() to create an explicit docking node within an existing window.
-// Note that you already dock windows into each others _without_ a DockSpace() by just moving windows
-// from their title bar (or by holding SHIFT if io.ConfigDockingWithShift is set).
-// DockSpace() is only useful to construct to a central location for your application.
+// Note that you dock windows into each others _without_ a dockspace, by just clicking on
+// a window title bar and moving it (+ hold SHIFT if io.ConfigDockingWithShift is set).
+// DockSpace() and DockSpaceOverViewport() are only useful to construct a central docking
+// location for your application.
 void ShowExampleAppDockSpace(bool* p_open)
 {
+    // In 99% case you should be able to just call DockSpaceOverViewport() and ignore all the code below!
+    // In this specific demo, we are not using DockSpaceOverViewport() because:
+    // - we allow the host window to be floating/moveable instead of filling the viewport (when opt_fullscreen == false)
+    // - we allow the host window to have padding (when opt_padding == true)
+    // - we have a local menu bar in the host window (vs. you could use BeginMainMenuBar() + DockSpaceOverViewport() in your code!)
+    // TL;DR; this demo is more complicated than what you would normally use.
+    // If we removed all the options we are showcasing, this demo would become:
+    //     void ShowExampleAppDockSpace()
+    //     {
+    //         ImGui::DockSpaceOverViewport(ImGui::GetMainViewport());
+    //     }
+
     static bool opt_fullscreen = true;
     static bool opt_padding = false;
     static ImGuiDockNodeFlags dockspace_flags = ImGuiDockNodeFlags_None;

imgui_internal.h

@@ -1942,17 +1942,18 @@ struct ImGuiTabItem
     float               Width;                  // Width currently displayed
     float               ContentWidth;           // Width of label, stored during BeginTabItem() call
     ImS16               NameOffset;             // When Window==NULL, offset to name within parent ImGuiTabBar::TabsNames
-    ImS8                BeginOrder;             // BeginTabItem() order, used to re-order tabs after toggling ImGuiTabBarFlags_Reorderable
-    ImS8                IndexDuringLayout;      // Index only used during TabBarLayout()
+    ImS16               BeginOrder;             // BeginTabItem() order, used to re-order tabs after toggling ImGuiTabBarFlags_Reorderable
+    ImS16               IndexDuringLayout;      // Index only used during TabBarLayout()
     bool                WantClose;              // Marked as closed by SetTabItemClosed()
 
-    ImGuiTabItem()      { ID = 0; Flags = ImGuiTabItemFlags_None; Window = NULL; LastFrameVisible = LastFrameSelected = -1; NameOffset = -1; Offset = Width = ContentWidth = 0.0f; BeginOrder = -1; IndexDuringLayout = -1; WantClose = false; }
+    ImGuiTabItem()      { memset(this, 0, sizeof(*this)); LastFrameVisible = LastFrameSelected = -1; NameOffset = BeginOrder = IndexDuringLayout = -1; }
 };
 
-// Storage for a tab bar (sizeof() 92~96 bytes)
+// Storage for a tab bar (sizeof() 152 bytes)
 struct ImGuiTabBar
 {
     ImVector<ImGuiTabItem> Tabs;
+    ImGuiTabBarFlags    Flags;
     ImGuiID             ID;                     // Zero for tab-bars used by docking
     ImGuiID             SelectedTabId;          // Selected tab/window
     ImGuiID             NextSelectedTabId;
@@ -1970,16 +1971,17 @@ struct ImGuiTabBar
     float               ScrollingSpeed;
     float               ScrollingRectMinX;
     float               ScrollingRectMaxX;
-    ImGuiTabBarFlags    Flags;
     ImGuiID             ReorderRequestTabId;
     ImS8                ReorderRequestDir;
-    ImS8                TabsActiveCount;        // Number of tabs submitted this frame.
+    ImS8                BeginCount;
     bool                WantLayout;
     bool                VisibleTabWasSubmitted;
     bool                TabsAddedNew;           // Set to true when a new tab item or button has been added to the tab bar during last frame
-    short               LastTabItemIdx;         // Index of last BeginTabItem() tab for use by EndTabItem()
+    ImS16               TabsActiveCount;        // Number of tabs submitted this frame.
+    ImS16               LastTabItemIdx;         // Index of last BeginTabItem() tab for use by EndTabItem()
+    float               ItemSpacingY;
     ImVec2              FramePadding;           // style.FramePadding locked at the time of BeginTabBar()
-    ImVec2              TabsContentsMin;
+    ImVec2              BackupCursorPos;
     ImGuiTextBuffer     TabsNames;              // For non-docking tab bar we re-append names in a contiguous buffer.
 
     ImGuiTabBar();
@@ -2234,7 +2236,7 @@ namespace ImGui
     IMGUI_API bool          TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags, ImGuiWindow* docked_window);
     IMGUI_API ImVec2        TabItemCalcSize(const char* label, bool has_close_button);
     IMGUI_API void          TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImU32 col);
-    IMGUI_API bool          TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible);
+    IMGUI_API void          TabItemLabelAndCloseButton(ImDrawList* draw_list, const ImRect& bb, ImGuiTabItemFlags flags, ImVec2 frame_padding, const char* label, ImGuiID tab_id, ImGuiID close_button_id, bool is_contents_visible, bool* out_just_closed, bool* out_text_clipped);
 
     // Render helpers
     // AVOID USING OUTSIDE OF IMGUI.CPP! NOT FOR PUBLIC CONSUMPTION. THOSE FUNCTIONS ARE A MESS. THEIR SIGNATURE AND BEHAVIOR WILL CHANGE, THEY NEED TO BE REFACTORED INTO SOMETHING DECENT.