From f48f9a30ef5f598e3fa9ac42e07a89b78c5dbc74 Mon Sep 17 00:00:00 2001
From: ocornut <omarcornut@gmail.com>
Date: Fri, 13 May 2016 11:13:54 +0200
Subject: [PATCH] ButtonBehavior(), fixed subtle old bug when a repeating
 button would also return true on release + comments (#656)

---
 imgui.cpp | 18 ++++++++++++------
 imgui.h   |  2 +-
 2 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/imgui.cpp b/imgui.cpp
index bee8bb79..a9e64892 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -5341,7 +5341,12 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
         SetHoveredID(id);
         if (!(flags & ImGuiButtonFlags_NoKeyModifiers) || (!g.IO.KeyCtrl && !g.IO.KeyShift && !g.IO.KeyAlt))
         {
-            if ((flags & ImGuiButtonFlags_PressedOnClickRelease) && g.IO.MouseClicked[0])   // Most common type
+            //                        | CLICKING        | HOLDING with ImGuiButtonFlags_Repeat
+            // PressedOnClickRelease  |  <on release>*  |  <on repeat> <on repeat> .. (NOT on release)  <-- MOST COMMON! (*) only if both click/release were over bounds
+            // PressedOnClick         |  <on click>     |  <on click> <on repeat> <on repeat> ..
+            // PressedOnRelease       |  <on release>   |  <on repeat> <on repeat> .. (NOT on release)
+            // PressedOnDoubleClick   |  <on dclick>    |  <on dclick> <on repeat> <on repeat> ..
+            if ((flags & ImGuiButtonFlags_PressedOnClickRelease) && g.IO.MouseClicked[0])
             {
                 SetActiveID(id, window); // Hold on ID
                 FocusWindow(window);
@@ -5354,13 +5359,13 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
             }
             if ((flags & ImGuiButtonFlags_PressedOnRelease) && g.IO.MouseReleased[0])
             {
-                pressed = true;
+                if (!((flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[0] >= g.IO.KeyRepeatDelay))  // Repeat mode trumps <on release>
+                    pressed = true;
                 SetActiveID(0);
             }
 
-            // 'Repeat' mode acts when held regardless of _PressedOn flags
-            // FIXME: Need to clarify the repeat behavior with those differents flags. Currently the typical PressedOnClickRelease+Repeat will add an extra click on final release (hardly noticeable with repeat rate, but technically an issue)
-            // Relies on repeat behavior of IsMouseClicked() but we may as well do it ourselves if we end up exposing finer RepeatDelay/RepeatRate settings.
+            // 'Repeat' mode acts when held regardless of _PressedOn flags (see table above). 
+            // Relies on repeat logic of IsMouseClicked() but we may as well do it ourselves if we end up exposing finer RepeatDelay/RepeatRate settings.
             if ((flags & ImGuiButtonFlags_Repeat) && g.ActiveId == id && g.IO.MouseDownDuration[0] > 0.0f && ImGui::IsMouseClicked(0, true))
                 pressed = true;
         }
@@ -5376,7 +5381,8 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
         else
         {
             if (hovered && (flags & ImGuiButtonFlags_PressedOnClickRelease))
-                pressed = true;
+                if (!((flags & ImGuiButtonFlags_Repeat) && g.IO.MouseDownDurationPrev[0] >= g.IO.KeyRepeatDelay))  // Repeat mode trumps <on release>
+                    pressed = true;
             SetActiveID(0);
         }
     }
diff --git a/imgui.h b/imgui.h
index fecfe3bf..38e36762 100644
--- a/imgui.h
+++ b/imgui.h
@@ -732,7 +732,7 @@ struct ImGuiIO
     float         MouseDoubleClickMaxDist;  // = 6.0f               // Distance threshold to stay in to validate a double-click, in pixels.
     float         MouseDragThreshold;       // = 6.0f               // Distance threshold before considering we are dragging
     int           KeyMap[ImGuiKey_COUNT];   // <unset>              // Map of indices into the KeysDown[512] entries array
-    float         KeyRepeatDelay;           // = 0.250f             // When holding a key/button, time before it starts repeating, in seconds. (for actions where 'repeat' is active)
+    float         KeyRepeatDelay;           // = 0.250f             // When holding a key/button, time before it starts repeating, in seconds (for buttons in Repeat mode, etc.).
     float         KeyRepeatRate;            // = 0.020f             // When holding a key/button, rate at which it repeats, in seconds.
     void*         UserData;                 // = NULL               // Store your own data for retrieval by callbacks.