Internals: Added GetInputTextState() + comments.

docs/TODO.txt

@@ -41,7 +41,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - scrolling: allow immediately effective change of scroll after Begin() if we haven't appended items yet.
  - scrolling: forward mouse wheel scrolling to parent window when at the edge of scrolling limits? (useful for listbox,tables?)
  - scrolling/clipping: separator on the initial position of a window is not visible (cursorpos.y <= clippos.y). (2017-08-20: can't repro)
- - scrolling/style: shadows on scrollable areas to denote that there is more contents
+ - scrolling/style: shadows on scrollable areas to denote that there is more contents (see e.g. DaVinci Resolve ui)
 
  - drawdata: make it easy to clone (or swap?) a full ImDrawData so user can easily save that data if they use threaded rendering. (e.g. #2646)
  ! drawlist: add calctextsize func to facilitate consistent code from user pov (currently need to use ImGui or ImFont alternatives!)
@@ -294,6 +294,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - font: a CalcTextHeight() helper could run faster than CalcTextSize().y
  - font: enforce monospace through ImFontConfig (for icons?) + create dual ImFont output from same input, reusing rasterized data but with different glyphs/AdvanceX
  - font: finish CustomRectRegister() to allow mapping Unicode codepoint to custom texture data
+ - font: remove ID from CustomRect registration, it seems unnecessary!
  - font: make it easier to submit own bitmap font (same texture, another texture?). (#2127, #2575)
  - font: PushFontSize API (#1018)
  - font: MemoryTTF taking ownership confusing/not obvious, maybe default should be opposite?
@@ -377,6 +378,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
 
  - examples: window minimize, maximize (#583)
  - examples: provide a zero frame-rate/idle example.
+ - examples: dx11/dx12: try to use new swapchain blit models (#2970)
  - backends: apple: example_apple should be using modern GL3.
  - backends: glfw: could go idle when minimized? if (glfwGetWindowAttrib(window, GLFW_ICONIFIED)) { glfwWaitEvents(); continue; } // issue: DeltaTime will be super high on resume, perhaps provide a way to let impl know (#440)
  - backends: opengl: rename imgui_impl_opengl2 to impl_opengl_legacy and imgui_impl_opengl3 to imgui_impl_opengl? (#1900)

examples/imgui_impl_glfw.h

@@ -25,8 +25,9 @@ IMGUI_IMPL_API bool     ImGui_ImplGlfw_InitForVulkan(GLFWwindow* window, bool in
 IMGUI_IMPL_API void     ImGui_ImplGlfw_Shutdown();
 IMGUI_IMPL_API void     ImGui_ImplGlfw_NewFrame();
 
-// InitXXX function with 'install_callbacks=true': install GLFW callbacks. They will call user's previously installed callbacks, if any.
-// InitXXX function with 'install_callbacks=false': do not install GLFW callbacks. You will need to call them yourself from your own GLFW callbacks.
+// GLFW callbacks
+// - When calling Init with 'install_callbacks=true': GLFW callbacks will be installed for you. They will call user's previously installed callbacks, if any.
+// - When calling Init with 'install_callbacks=false': GLFW callbacks won't be installed. You will need to call those function yourself from your own GLFW callbacks.
 IMGUI_IMPL_API void     ImGui_ImplGlfw_MouseButtonCallback(GLFWwindow* window, int button, int action, int mods);
 IMGUI_IMPL_API void     ImGui_ImplGlfw_ScrollCallback(GLFWwindow* window, double xoffset, double yoffset);
 IMGUI_IMPL_API void     ImGui_ImplGlfw_KeyCallback(GLFWwindow* window, int key, int scancode, int action, int mods);

imgui.cpp

@@ -1570,6 +1570,7 @@ ImU64   ImFileWrite(const void* data, ImU64 sz, ImU64 count, ImFileHandle f)
 
 // Helper: Load file content into memory
 // Memory allocated with IM_ALLOC(), must be freed by user using IM_FREE() == ImGui::MemFree()
+// This can't really be used with "rt" because fseek size won't match read size.
 void*   ImFileLoadToMemory(const char* filename, const char* mode, size_t* out_file_size, int padding_bytes)
 {
     IM_ASSERT(filename && mode);

imgui_internal.h

@@ -746,10 +746,11 @@ struct IMGUI_API ImGuiMenuColumns
 };
 
 // Internal state of the currently focused/edited text input box
+// For a given item ID, access with ImGui::GetInputTextState()
 struct IMGUI_API ImGuiInputTextState
 {
     ImGuiID                 ID;                     // widget id owning the text state
-    int                     CurLenW, CurLenA;       // we need to maintain our buffer length in both UTF-8 and wchar format. UTF-8 len is valid even if TextA is not.
+    int                     CurLenW, CurLenA;       // we need to maintain our buffer length in both UTF-8 and wchar format. UTF-8 length is valid even if TextA is not.
     ImVector<ImWchar>       TextW;                  // edit buffer, we need to persist but can't guarantee the persistence of the user-provided buffer. so we copy into own buffer.
     ImVector<char>          TextA;                  // temporary UTF8 buffer for callbacks and other operations. this is not updated in every code-path! size=capacity.
     ImVector<char>          InitialTextA;           // backup of end-user buffer at the time of focus (in UTF-8, unaltered)
@@ -1850,6 +1851,7 @@ namespace ImGui
     IMGUI_API bool          TempInputText(const ImRect& bb, ImGuiID id, const char* label, char* buf, int buf_size, ImGuiInputTextFlags flags);
     IMGUI_API bool          TempInputScalar(const ImRect& bb, ImGuiID id, const char* label, ImGuiDataType data_type, void* p_data, const char* format);
     inline bool             TempInputIsActive(ImGuiID id)       { ImGuiContext& g = *GImGui; return (g.ActiveId == id && g.TempInputId == id); }
+    inline ImGuiInputTextState* GetInputTextState(ImGuiID id)   { ImGuiContext& g = *GImGui; return (g.InputTextState.ID == id) ? &g.InputTextState : NULL; } // Get input text state if active
 
     // Color
     IMGUI_API void          ColorTooltip(const char* text, const float* col, ImGuiColorEditFlags flags);

imgui_widgets.cpp

@@ -3516,10 +3516,8 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_
     if (hovered)
         g.MouseCursor = ImGuiMouseCursor_TextInput;
 
-    // NB: we are only allowed to access 'edit_state' if we are the active widget.
-    ImGuiInputTextState* state = NULL;
-    if (g.InputTextState.ID == id)
-        state = &g.InputTextState;
+    // We are only allowed to access the state if we are already the active widget.
+    ImGuiInputTextState* state = GetInputTextState(id);
 
     const bool focus_requested = FocusableItemRegister(window, id);
     const bool focus_requested_by_code = focus_requested && (g.FocusRequestCurrWindow == window && g.FocusRequestCurrCounterRegular == window->DC.FocusCounterRegular);