InvisibleButton: Made public a small selection of ImGuiButtonFlags (previously in imgui_internal.h) and allowed to pass them to InvisibleButton().

docs/CHANGELOG.txt

@@ -49,6 +49,11 @@ Other Changes:
   clipping, more than 16 KB characters are visible in the same low-level ImDrawList::RenderText
   call. ImGui-level functions such as TextUnformatted() are not affected. This is quite rare
   but it will be addressed later). (#3349)
+- InvisibleButton: Made public a small selection of ImGuiButtonFlags (previously in imgui_internal.h)
+  and allowed to pass them to InvisibleButton(): ImGuiButtonFlags_MouseButtonLeft/Right/Middle.
+  This is a small but rather important change because lots of multi-button behaviors could previously
+  only be achieved using lower-level/internal API. Now also available via high-level InvisibleButton()
+  with is a de-facto versatile building block to creating custom widgets with the public API.
 - Fonts: Fixed ImFontConfig::GlyphExtraSpacing and ImFontConfig::PixelSnapH settings being pulled
   from the merged/target font settings when merging fonts, instead of being pulled from the source
   font settings.

docs/TODO.txt

@@ -207,6 +207,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - popups: clicking outside (to close popup) and holding shouldn't drag window below.
  - popups: add variant using global identifier similar to Begin/End (#402)
  - popups: border options. richer api like BeginChild() perhaps? (#197)
+ - popups: flags could be reworked to allow both mouse buttons as index (0..5 and as flags using higher-bit) allowing to or them.
  - popups/modals: although it is sometimes convenient that popups/modals lifetime is owned by imgui, we could also a bool-owned-by-user api as long as Begin() return value testing is enforced.
 
  - tooltip: drag and drop with tooltip near monitor edges lose/changes its last direction instead of locking one. The drag and drop tooltip should always follow without changing direction.

imgui.cpp

@@ -4455,6 +4455,7 @@ bool ImGui::IsMouseDoubleClicked(ImGuiMouseButton button)
     return g.IO.MouseDoubleClicked[button];
 }
 
+// Return if a mouse click/drag went past the given threshold. Valid to call during the MouseReleased frame.
 // [Internal] This doesn't test if the button is pressed
 bool ImGui::IsMouseDragPastThreshold(ImGuiMouseButton button, float lock_threshold)
 {
@@ -7848,6 +7849,7 @@ void ImGui::EndPopup()
     g.WithinEndChild = false;
 }
 
+// Open a popup if mouse is released over the item
 bool ImGui::OpenPopupContextItem(const char* str_id, ImGuiPopupFlags popup_flags)
 {
     ImGuiWindow* window = GImGui->CurrentWindow;

imgui.h

@@ -153,6 +153,7 @@ typedef int ImDrawCornerFlags;      // -> enum ImDrawCornerFlags_    // Flags: f
 typedef int ImDrawListFlags;        // -> enum ImDrawListFlags_      // Flags: for ImDrawList
 typedef int ImFontAtlasFlags;       // -> enum ImFontAtlasFlags_     // Flags: for ImFontAtlas build
 typedef int ImGuiBackendFlags;      // -> enum ImGuiBackendFlags_    // Flags: for io.BackendFlags
+typedef int ImGuiButtonFlags;       // -> enum ImGuiButtonFlags_     // Flags: for InvisibleButton()
 typedef int ImGuiColorEditFlags;    // -> enum ImGuiColorEditFlags_  // Flags: for ColorEdit4(), ColorPicker4() etc.
 typedef int ImGuiConfigFlags;       // -> enum ImGuiConfigFlags_     // Flags: for io.ConfigFlags
 typedef int ImGuiComboFlags;        // -> enum ImGuiComboFlags_      // Flags: for BeginCombo()
@@ -437,7 +438,7 @@ namespace ImGui
     // - You may also use one of the many IsItemXXX functions (e.g. IsItemActive, IsItemHovered, etc.) to query widget state.
     IMGUI_API bool          Button(const char* label, const ImVec2& size = ImVec2(0, 0));   // button
     IMGUI_API bool          SmallButton(const char* label);                                 // button with FramePadding=(0,0) to easily embed within text
-    IMGUI_API bool          InvisibleButton(const char* str_id, const ImVec2& size);        // button behavior without the visuals, frequently useful to build custom behaviors using the public api (along with IsItemActive, IsItemHovered, etc.)
+    IMGUI_API bool          InvisibleButton(const char* str_id, const ImVec2& size, ImGuiButtonFlags flags = 0); // flexible button behavior without the visuals, frequently useful to build custom behaviors using the public api (along with IsItemActive, IsItemHovered, etc.)
     IMGUI_API bool          ArrowButton(const char* str_id, ImGuiDir dir);                  // square button with an arrow shape
     IMGUI_API void          Image(ImTextureID user_texture_id, const ImVec2& size, const ImVec2& uv0 = ImVec2(0, 0), const ImVec2& uv1 = ImVec2(1,1), const ImVec4& tint_col = ImVec4(1,1,1,1), const ImVec4& border_col = ImVec4(0,0,0,0));
     IMGUI_API bool          ImageButton(ImTextureID user_texture_id, const ImVec2& size, const ImVec2& uv0 = ImVec2(0, 0),  const ImVec2& uv1 = ImVec2(1,1), int frame_padding = -1, const ImVec4& bg_col = ImVec4(0,0,0,0), const ImVec4& tint_col = ImVec4(1,1,1,1));    // <0 frame_padding uses default frame padding settings. 0 for no padding
@@ -446,7 +447,7 @@ namespace ImGui
     IMGUI_API bool          RadioButton(const char* label, bool active);                    // use with e.g. if (RadioButton("one", my_value==1)) { my_value = 1; }
     IMGUI_API bool          RadioButton(const char* label, int* v, int v_button);           // shortcut to handle the above pattern when value is an integer
     IMGUI_API void          ProgressBar(float fraction, const ImVec2& size_arg = ImVec2(-1, 0), const char* overlay = NULL);
-    IMGUI_API void          Bullet();                                                       // draw a small circle and keep the cursor on the same line. advance cursor x position by GetTreeNodeToLabelSpacing(), same distance that TreeNode() uses
+    IMGUI_API void          Bullet();                                                       // draw a small circle + keep the cursor on the same line. advance cursor x position by GetTreeNodeToLabelSpacing(), same distance that TreeNode() uses
 
     // Widgets: Combo Box
     // - The BeginCombo()/EndCombo() api allows you to manage your contents and selection state however you want it, by creating e.g. Selectable() items.
@@ -877,6 +878,7 @@ enum ImGuiTreeNodeFlags_
 //   small flags values as a mouse button index, so we encode the mouse button in the first few bits of the flags.
 //   It is therefore guaranteed to be legal to pass a mouse button index in ImGuiPopupFlags.
 // - For the same reason, we exceptionally default the ImGuiPopupFlags argument of BeginPopupContextXXX functions to 1 instead of 0.
+// - Multiple buttons currently cannot be combined/or-ed in those functions (we could allow it later).
 enum ImGuiPopupFlags_
 {
     ImGuiPopupFlags_None                    = 0,
@@ -1221,6 +1223,19 @@ enum ImGuiStyleVar_
 #endif
 };
 
+// Flags for InvisibleButton() [extended in imgui_internal.h]
+enum ImGuiButtonFlags_
+{
+    ImGuiButtonFlags_None                   = 0,
+    ImGuiButtonFlags_MouseButtonLeft        = 1 << 0,   // React on left mouse button (default)
+    ImGuiButtonFlags_MouseButtonRight       = 1 << 1,   // React on right mouse button
+    ImGuiButtonFlags_MouseButtonMiddle      = 1 << 2,   // React on center mouse button
+
+    // [Internal]
+    ImGuiButtonFlags_MouseButtonMask_       = ImGuiButtonFlags_MouseButtonLeft | ImGuiButtonFlags_MouseButtonRight | ImGuiButtonFlags_MouseButtonMiddle,
+    ImGuiButtonFlags_MouseButtonDefault_    = ImGuiButtonFlags_MouseButtonLeft
+};
+
 // Flags for ColorEdit3() / ColorEdit4() / ColorPicker3() / ColorPicker4() / ColorButton()
 enum ImGuiColorEditFlags_
 {

imgui_internal.h

@@ -604,32 +604,25 @@ enum ImGuiItemStatusFlags_
 #endif
 };
 
-enum ImGuiButtonFlags_
+// Extend ImGuiButtonFlags_
+enum ImGuiButtonFlagsPrivate_
 {
-    ImGuiButtonFlags_None                   = 0,
+    ImGuiButtonFlags_PressedOnClick         = 1 << 4,   // return true on click (mouse down event)
-    ImGuiButtonFlags_Repeat                 = 1 << 0,   // hold to repeat
+    ImGuiButtonFlags_PressedOnClickRelease  = 1 << 5,   // [Default] return true on click + release on same item <-- this is what the majority of Button are using
-    ImGuiButtonFlags_PressedOnClick         = 1 << 1,   // return true on click (mouse down event)
+    ImGuiButtonFlags_PressedOnClickReleaseAnywhere = 1 << 6, // return true on click + release even if the release event is not done while hovering the item
-    ImGuiButtonFlags_PressedOnClickRelease  = 1 << 2,   // [Default] return true on click + release on same item <-- this is what the majority of Button are using
+    ImGuiButtonFlags_PressedOnRelease       = 1 << 7,   // return true on release (default requires click+release)
-    ImGuiButtonFlags_PressedOnClickReleaseAnywhere = 1 << 3, // return true on click + release even if the release event is not done while hovering the item
+    ImGuiButtonFlags_PressedOnDoubleClick   = 1 << 8,   // return true on double-click (default requires click+release)
-    ImGuiButtonFlags_PressedOnRelease       = 1 << 4,   // return true on release (default requires click+release)
+    ImGuiButtonFlags_PressedOnDragDropHold  = 1 << 9,   // return true when held into while we are drag and dropping another item (used by e.g. tree nodes, collapsing headers)
-    ImGuiButtonFlags_PressedOnDoubleClick   = 1 << 5,   // return true on double-click (default requires click+release)
+    ImGuiButtonFlags_Repeat                 = 1 << 10,  // hold to repeat
-    ImGuiButtonFlags_PressedOnDragDropHold  = 1 << 6,   // return true when held into while we are drag and dropping another item (used by e.g. tree nodes, collapsing headers)
+    ImGuiButtonFlags_FlattenChildren        = 1 << 11,  // allow interactions even if a child window is overlapping
-    ImGuiButtonFlags_FlattenChildren        = 1 << 7,   // allow interactions even if a child window is overlapping
+    ImGuiButtonFlags_AllowItemOverlap       = 1 << 12,  // require previous frame HoveredId to either match id or be null before being usable, use along with SetItemAllowOverlap()
-    ImGuiButtonFlags_AllowItemOverlap       = 1 << 8,   // require previous frame HoveredId to either match id or be null before being usable, use along with SetItemAllowOverlap()
+    ImGuiButtonFlags_DontClosePopups        = 1 << 13,  // disable automatically closing parent popup on press // [UNUSED]
-    ImGuiButtonFlags_DontClosePopups        = 1 << 9,   // disable automatically closing parent popup on press // [UNUSED]
+    ImGuiButtonFlags_Disabled               = 1 << 14,  // disable interactions
-    ImGuiButtonFlags_Disabled               = 1 << 10,  // disable interactions
+    ImGuiButtonFlags_AlignTextBaseLine      = 1 << 15,  // vertically align button to match text baseline - ButtonEx() only // FIXME: Should be removed and handled by SmallButton(), not possible currently because of DC.CursorPosPrevLine
-    ImGuiButtonFlags_AlignTextBaseLine      = 1 << 11,  // vertically align button to match text baseline - ButtonEx() only // FIXME: Should be removed and handled by SmallButton(), not possible currently because of DC.CursorPosPrevLine
+    ImGuiButtonFlags_NoKeyModifiers         = 1 << 16,  // disable mouse interaction if a key modifier is held
-    ImGuiButtonFlags_NoKeyModifiers         = 1 << 12,  // disable mouse interaction if a key modifier is held
+    ImGuiButtonFlags_NoHoldingActiveId      = 1 << 17,  // don't set ActiveId while holding the mouse (ImGuiButtonFlags_PressedOnClick only)
-    ImGuiButtonFlags_NoHoldingActiveId      = 1 << 13,  // don't set ActiveId while holding the mouse (ImGuiButtonFlags_PressedOnClick only)
+    ImGuiButtonFlags_NoNavFocus             = 1 << 18,  // don't override navigation focus when activated
-    ImGuiButtonFlags_NoNavFocus             = 1 << 14,  // don't override navigation focus when activated
+    ImGuiButtonFlags_NoHoveredOnFocus       = 1 << 19,  // don't report as hovered when nav focus is on this item
-    ImGuiButtonFlags_NoHoveredOnFocus       = 1 << 15,  // don't report as hovered when nav focus is on this item
-    ImGuiButtonFlags_MouseButtonLeft        = 1 << 16,  // [Default] react on left mouse button
-    ImGuiButtonFlags_MouseButtonRight       = 1 << 17,  // react on right mouse button
-    ImGuiButtonFlags_MouseButtonMiddle      = 1 << 18,  // react on center mouse button
-
-    ImGuiButtonFlags_MouseButtonMask_       = ImGuiButtonFlags_MouseButtonLeft | ImGuiButtonFlags_MouseButtonRight | ImGuiButtonFlags_MouseButtonMiddle,
-    ImGuiButtonFlags_MouseButtonShift_      = 16,
-    ImGuiButtonFlags_MouseButtonDefault_    = ImGuiButtonFlags_MouseButtonLeft,
     ImGuiButtonFlags_PressedOnMask_         = ImGuiButtonFlags_PressedOnClick | ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnClickReleaseAnywhere | ImGuiButtonFlags_PressedOnRelease | ImGuiButtonFlags_PressedOnDoubleClick | ImGuiButtonFlags_PressedOnDragDropHold,
     ImGuiButtonFlags_PressedOnDefault_      = ImGuiButtonFlags_PressedOnClickRelease
 };

imgui_widgets.cpp

@@ -685,7 +685,7 @@ bool ImGui::ButtonEx(const char* label, const ImVec2& size_arg, ImGuiButtonFlags
 
 bool ImGui::Button(const char* label, const ImVec2& size_arg)
 {
-    return ButtonEx(label, size_arg, 0);
+    return ButtonEx(label, size_arg, ImGuiButtonFlags_None);
 }
 
 // Small buttons fits within text without additional vertical spacing.
@@ -701,7 +701,7 @@ bool ImGui::SmallButton(const char* label)
 
 // Tip: use ImGui::PushID()/PopID() to push indices or pointers in the ID stack.
 // Then you can keep 'str_id' empty or the same for all your buttons (instead of creating a string based on a non-string id)
-bool ImGui::InvisibleButton(const char* str_id, const ImVec2& size_arg)
+bool ImGui::InvisibleButton(const char* str_id, const ImVec2& size_arg, ImGuiButtonFlags flags)
 {
     ImGuiWindow* window = GetCurrentWindow();
     if (window->SkipItems)
@@ -718,7 +718,7 @@ bool ImGui::InvisibleButton(const char* str_id, const ImVec2& size_arg)
         return false;
 
     bool hovered, held;
-    bool pressed = ButtonBehavior(bb, id, &hovered, &held);
+    bool pressed = ButtonBehavior(bb, id, &hovered, &held, flags);
 
     return pressed;
 }