Popups: added comments, reorganized the functions in imgui.h

docs/CHANGELOG.txt

@@ -55,7 +55,7 @@ Other Changes:
 - Popups: Fix an edge case where programatically closing a popup while clicking on its empty space
   would attempt to focus it and close other popups. (#2880)
 - Popups: Fix BeginPopupContextVoid() when clicking over the area made unavailable by a modal. (#1636)
-- Fix GetGlyphRangesKorean() end-range to end at 0xD7A3 (instead of 0xD79D). (#348, #3217) [@marukrap]
+- Popups: Clarified some of the comments and function prototypes.
 - Metrics: Added a "Settings" section with some details about persistent ini settings.
 - Nav, Menus: Fix vertical wrap-around in menus or popups created with multiple appending calls to
   BeginMenu()/EndMenu() or BeginPopup/EndPopup(). (#3223, #1207) [@rokups]
@@ -63,6 +63,7 @@ Other Changes:
   drag source uses _SourceNoPreviewTooltip flags. (#3160) [@rokups]
 - Columns: Lower overhead on column switches and switching to background channel.
   Benefits Columns but was primarily made with Tables in mind!
+- Fonts: Fix GetGlyphRangesKorean() end-range to end at 0xD7A3 (instead of 0xD79D). (#348, #3217) [@marukrap]
 - ImDrawList: Fixed an issue where draw command merging or primitive unreserve while crossing the
   VtxOffset boundary would lead to draw commands with wrong VtxOffset. (#3129, #3163, #3232, #2591)
   [@thedmd, @Shironekoben, @sergeyn, @ocornut]

docs/TODO.txt

@@ -202,11 +202,13 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i
  - listbox: future api should allow to enable horizontal scrolling (#2510)
 
 !- popups/menus: clarify usage of popups id, how MenuItem/Selectable closing parent popups affects the ID, etc. this is quite fishy needs improvement! (#331, #402)
- - popups/modal: make modal title bar blink when trying to click outside the modal
+ - modals: make modal title bar blink when trying to click outside the modal
+ - modals: technically speaking, we could make Begin() with ImGuiWindowFlags_Modal work without involving popup. May help untangle a few things, as modals are more like regular windows than popups.
  - popups: if the popup functions took explicit ImGuiID it would allow the user to manage the scope of those ID. (#331)
  - 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/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.
  - tooltip: tooltip that doesn't fit in entire screen seems to lose their "last preferred direction" and may teleport when moving mouse.

imgui.cpp

@@ -7891,7 +7891,7 @@ bool ImGui::OpenPopupContextItem(const char* str_id, ImGuiMouseButton mouse_butt
 // This is a helper to handle the simplest case of associating one named popup to one given widget.
 // - You can pass a NULL str_id to use the identifier of the last item.
 // - You may want to handle this on user side if you have specific needs (e.g. tweaking IsItemHovered() parameters).
-// - This is essentially the same as calling OpenPopupContextItem() + BeginPopupEx() but written to avoid
+// - This is essentially the same as calling OpenPopupContextItem() + BeginPopup() but written to avoid
 //   computing the ID twice because BeginPopupContextXXX functions are called very frequently.
 bool ImGui::BeginPopupContextItem(const char* str_id, ImGuiMouseButton mouse_button)
 {

imgui.h

@@ -591,28 +591,34 @@ namespace ImGui
     IMGUI_API void          SetTooltipV(const char* fmt, va_list args) IM_FMTLIST(1);
 
     // Popups, Modals
-    // The properties of popups windows are:
-    // - They block normal mouse hovering detection outside them. (*1)
-    // - Unless modal, they can be closed by clicking anywhere outside them, or by pressing ESCAPE.
-    //   Because hovering detection is disabled outside the popup, when clicking outside the click will not be seen by underlying widgets! (*1)
-    // - Their visibility state (~bool) is held internally by Dear ImGui instead of being held by the programmer as we are used to with regular Begin() calls.
-    //   User can manipulate the visibility state by calling OpenPopup(), CloseCurrentPopup() etc.
-    // - We default to use the right mouse (ImGuiMouseButton_Right=1) for the Popup Context functions.
-    // Those three properties are connected: we need to retain popup visibility state in the library because popups may be closed as any time.
-    // (*1) You can bypass that restriction and detect hovering even when normally blocked by a popup.
-    //      To do this use the ImGuiHoveredFlags_AllowWhenBlockedByPopup when calling IsItemHovered() or IsWindowHovered().
-    //      This is what BeginPopupContextItem() and BeginPopupContextWindow() are doing already, allowing a right-click to reopen another popups without losing the click.
-    // - The BeginPopupContextXXX functions are essentially helpers to do an OpenPopup() in some condition + BeginPopup().
-    IMGUI_API void          OpenPopup(const char* str_id);                                      // call to mark popup as open (don't call every frame!). popups are closed when user click outside, or if CloseCurrentPopup() is called within a BeginPopup()/EndPopup() block. By default, Selectable()/MenuItem() are calling CloseCurrentPopup(). Popup identifiers are relative to the current ID-stack (so OpenPopup and BeginPopup needs to be at the same level).
-    IMGUI_API bool          BeginPopup(const char* str_id, ImGuiWindowFlags flags = 0);                                             // return true if the popup is open, and you can start outputting to it. only call EndPopup() if BeginPopup() returns true!
-    IMGUI_API bool          BeginPopupContextItem(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1);                    // helper to open and begin popup when clicked on last item. if you can pass a NULL str_id only if the previous item had an id. If you want to use that on a non-interactive item such as Text() you need to pass in an explicit ID here. read comments in .cpp!
-    IMGUI_API bool          BeginPopupContextWindow(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1, bool also_over_items = true);  // helper to open and begin popup when clicked on current window.
-    IMGUI_API bool          BeginPopupContextVoid(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1);                    // helper to open and begin popup when clicked in void (where there are no imgui windows).
-    IMGUI_API bool          BeginPopupModal(const char* name, bool* p_open = NULL, ImGuiWindowFlags flags = 0);                     // modal dialog (regular window with title bar, block interactions behind the modal window, can't close the modal window by clicking outside)
-    IMGUI_API void          EndPopup();                                                                                             // only call EndPopup() if BeginPopupXXX() returns true!
-    IMGUI_API bool          OpenPopupContextItem(const char* str_id = NULL, ImGuiMouseButton mouse_button = 1);                     // helper to open popup when clicked on last item. return true when just opened. (note: actually triggers on the mouse _released_ event to be consistent with popup behaviors)
-    IMGUI_API bool          IsPopupOpen(const char* str_id);                                    // return true if the popup is open at the current BeginPopup() level of the popup stack
-    IMGUI_API void          CloseCurrentPopup();                                                // close the popup we have begin-ed into. clicking on a MenuItem or Selectable automatically close the current popup.
+    //  - They block normal mouse hovering detection (and therefore most mouse interactions) behind them.
+    //  - If not modal: they can be closed by clicking anywhere outside them, or by pressing ESCAPE.
+    //  - Their visibility state (~bool) is held internally instead of being held by the programmer as we are used to with regular Begin*() calls.
+    //  - The 3 properties above are related: we need to retain popup visibility state in the library because popups may be closed as any time.
+    //  - You can bypass the hovering restriction by using ImGuiHoveredFlags_AllowWhenBlockedByPopup when calling IsItemHovered() or IsWindowHovered().
+    //  - IMPORTANT: Popup identifiers are relative to the current ID stack, so OpenPopup and BeginPopup generally needs to be at the same level of the stack.
+    //    This is sometimes leading to confusing mistakes. May rework this in the future.
+    // Popups: begin/end functions
+    //  - BeginPopup(): query popup state, if open start appending into the window. Call EndPopup() afterwards. ImGuiWindowFlags are forwarded to the window.
+    //  - BeginPopupModal(): block every interactions behind the window, cannot be closed by user, add a dimming background, has a title bar.
+    IMGUI_API bool          BeginPopup(const char* str_id, ImGuiWindowFlags flags = 0);                         // return true if the popup is open, and you can start outputting to it.
+    IMGUI_API bool          BeginPopupModal(const char* name, bool* p_open = NULL, ImGuiWindowFlags flags = 0); // return true if the modal is open, and you can start outputting to it.
+    IMGUI_API void          EndPopup();                                                                         // only call EndPopup() if BeginPopupXXX() returns true!
+    // Popups: open/close functions
+    //  - OpenPopup(): set popup state to open.
+    //  - If not modal: they can be closed by clicking anywhere outside them, or by pressing ESCAPE.
+    //  - CloseCurrentPopup(): use inside the BeginPopup()/EndPopup() scope to close manually.
+    //  - CloseCurrentPopup() is called by default by Selectable()/MenuItem() when activated (FIXME: need some options).
+    IMGUI_API void          OpenPopup(const char* str_id);                                                      // call to mark popup as open (don't call every frame!).
+    IMGUI_API bool          OpenPopupContextItem(const char* str_id = NULL, ImGuiMouseButton mouse_b = 1);      // helper to open popup when clicked on last item. return true when just opened. (note: actually triggers on the mouse _released_ event to be consistent with popup behaviors)
+    IMGUI_API void          CloseCurrentPopup();                                                                // manually close the popup we have begin-ed into.
+    IMGUI_API bool          IsPopupOpen(const char* str_id);                                                    // return true if the popup is open at the current BeginPopup() level of the popup stack
+    // Popups: open+begin combined functions helpers
+    //  - Helpers to do OpenPopup+BeginPopup where the Open action is triggered by e.g. hovering an item and right-clicking.
+    //  - They are convenient to easily create context menus, hence the name.
+    IMGUI_API bool          BeginPopupContextItem(const char* str_id = NULL, ImGuiMouseButton mouse_b = 1);     // open+begin popup when clicked on last item. if you can pass a NULL str_id only if the previous item had an id. If you want to use that on a non-interactive item such as Text() you need to pass in an explicit ID here. read comments in .cpp!
+    IMGUI_API bool          BeginPopupContextWindow(const char* str_id = NULL, ImGuiMouseButton mouse_b = 1, bool also_over_items = true);  // open+begin popup when clicked on current window.
+    IMGUI_API bool          BeginPopupContextVoid(const char* str_id = NULL, ImGuiMouseButton mouse_b = 1);     // open+begin popup when clicked in void (where there are no windows).
 
     // Columns
     // - You can also use SameLine(pos_x) to mimic simplified columns.