Demo: fix some id conflicts. (#7961)

imgui_demo.cpp

@@ -547,7 +547,7 @@ void ImGui::ShowDemoWindow(bool* p_open)
             ImGui::Checkbox("io.ConfigDebugIsDebuggerPresent", &io.ConfigDebugIsDebuggerPresent);
             ImGui::SameLine(); HelpMarker("Enable various tools calling IM_DEBUG_BREAK().\n\nRequires a debugger being attached, otherwise IM_DEBUG_BREAK() options will appear to crash your application.");
             ImGui::BeginDisabled();
-            ImGui::Checkbox("io.ConfigDebugBeginReturnValueOnce", &io.ConfigDebugBeginReturnValueOnce); // .
+            ImGui::Checkbox("io.ConfigDebugBeginReturnValueOnce", &io.ConfigDebugBeginReturnValueOnce);
             ImGui::EndDisabled();
             ImGui::SameLine(); HelpMarker("First calls to Begin()/BeginChild() will return false.\n\nTHIS OPTION IS DISABLED because it needs to be set at application boot-time to make sense. Showing the disabled option is a way to make this feature easier to discover.");
             ImGui::Checkbox("io.ConfigDebugBeginReturnValueLoop", &io.ConfigDebugBeginReturnValueLoop);
@@ -2000,8 +2000,8 @@ static void ShowDemoWindowWidgets(ImGuiDemoWindowData* demo_data)
         ImGui::SameLine();
         ImGui::SliderInt("Sample count", &display_count, 1, 400);
         float (*func)(void*, int) = (func_type == 0) ? Funcs::Sin : Funcs::Saw;
-        ImGui::PlotLines("Lines", func, NULL, display_count, 0, NULL, -1.0f, 1.0f, ImVec2(0, 80));
-        ImGui::PlotHistogram("Histogram", func, NULL, display_count, 0, NULL, -1.0f, 1.0f, ImVec2(0, 80));
+        ImGui::PlotLines("Lines##2", func, NULL, display_count, 0, NULL, -1.0f, 1.0f, ImVec2(0, 80));
+        ImGui::PlotHistogram("Histogram##2", func, NULL, display_count, 0, NULL, -1.0f, 1.0f, ImVec2(0, 80));
         ImGui::Separator();
 
         ImGui::Text("Need better plotting and graphing? Consider using ImPlot:");
@@ -2596,6 +2596,8 @@ static void ShowDemoWindowWidgets(ImGuiDemoWindowData* demo_data)
         IMGUI_DEMO_MARKER("Widgets/Drag and Drop/Drag to reorder items (simple)");
         if (ImGui::TreeNode("Drag to reorder items (simple)"))
         {
+            // FIXME: temporary ID Conflict during reordering as a same item may be submitting twice.
+
             // Simple reordering
             HelpMarker(
                 "We don't use the drag and drop api at all here! "
@@ -4225,7 +4227,7 @@ static void ShowDemoWindowLayout()
             // down by FramePadding.y ahead of time)
             ImGui::AlignTextToFramePadding();
             ImGui::Text("OK Blahblah"); ImGui::SameLine();
-            ImGui::Button("Some framed item"); ImGui::SameLine();
+            ImGui::Button("Some framed item##2"); ImGui::SameLine();
             HelpMarker("We call AlignTextToFramePadding() to vertically align the text baseline by +FramePadding.y");
 
             // SmallButton() uses the same vertical padding as Text
@@ -7148,12 +7150,14 @@ static void ShowDemoWindowColumns()
         {
             if (h_borders && ImGui::GetColumnIndex() == 0)
                 ImGui::Separator();
+            ImGui::PushID(i);
             ImGui::Text("%c%c%c", 'a' + i, 'a' + i, 'a' + i);
             ImGui::Text("Width %.2f", ImGui::GetColumnWidth());
             ImGui::Text("Avail %.2f", ImGui::GetContentRegionAvail().x);
             ImGui::Text("Offset %.2f", ImGui::GetColumnOffset());
             ImGui::Text("Long text that is likely to clip");
             ImGui::Button("Button", ImVec2(-FLT_MIN, 0.0f));
+            ImGui::PopID();
             ImGui::NextColumn();
         }
         ImGui::Columns(1);