From 3d48f5b8c296aba88c5df6b76dfc23f5f32fe581 Mon Sep 17 00:00:00 2001
From: omar <omarcornut@gmail.com>
Date: Mon, 25 Dec 2017 17:40:47 +0100
Subject: [PATCH] Demo: BeginCombo() demo code

---
 imgui.h        |  1 +
 imgui_demo.cpp | 26 +++++++++++++++++++++-----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/imgui.h b/imgui.h
index 10d46ab05..bd9571cfb 100644
--- a/imgui.h
+++ b/imgui.h
@@ -300,6 +300,7 @@ namespace ImGui
 
     // Widgets: Combo Box
     // The new BeginCombo()/EndCombo() api allows you to manage your contents and selection state however you want it. 
+    // The old Combo() api are helpers over BeginCombo()/EndCombo() which are kept available for convenience purpose.
     IMGUI_API bool          BeginCombo(const char* label, const char* preview_value, ImGuiComboFlags flags = 0);
     IMGUI_API void          EndCombo();
     IMGUI_API bool          Combo(const char* label, int* current_item, const char* const items[], int items_count, int popup_max_height_in_items = -1);
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 7a6a0fa21..966d80c52 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -322,12 +322,28 @@ void ImGui::ShowDemoWindow(bool* p_open)
 
             ImGui::LabelText("label", "Value");
 
-            static int item = 1;
-            ImGui::Combo("combo", &item, "aaaa\0bbbb\0cccc\0dddd\0eeee\0\0");   // Combo using values packed in a single constant string (for really quick combo)
+            {
+                // Simplified one-liner Combo() API, using values packed in a single constant string
+                static int current_item_1 = 1;
+                ImGui::Combo("combo", &current_item_1, "aaaa\0bbbb\0cccc\0dddd\0eeee\0\0");
+                //ImGui::Combo("combo w/ array of char*", &current_item_2_idx, items, IM_ARRAYSIZE(items));   // Combo using proper array. You can also pass a callback to retrieve array value, no need to create/copy an array just for that.
 
-            const char* items[] = { "AAAA", "BBBB", "CCCC", "DDDD", "EEEE", "FFFF", "GGGG", "HHHH", "IIII", "JJJJ", "KKKK", "LLLLLLL", "MMMM", "OOOOOOO", "PPPP", "QQQQQQQQQQ", "RRR", "SSSS" };
-            static int item2 = -1;
-            ImGui::Combo("combo scroll", &item2, items, IM_ARRAYSIZE(items));   // Combo using proper array. You can also pass a callback to retrieve array value, no need to create/copy an array just for that.
+                // General BeginCombo() API, you have full control over your selection data and display type
+                const char* items[] = { "AAAA", "BBBB", "CCCC", "DDDD", "EEEE", "FFFF", "GGGG", "HHHH", "IIII", "JJJJ", "KKKK", "LLLLLLL", "MMMM", "OOOOOOO", "PPPP", "QQQQQQQQQQ", "RRR", "SSSS" };
+                static const char* current_item_2 = NULL;
+                if (ImGui::BeginCombo("combo 2", current_item_2)) // The second parameter is the label previewed before opening the combo.
+                {
+                    for (int n = 0; n < IM_ARRAYSIZE(items); n++)
+                    {
+                        bool is_selected = (current_item_2 == items[n]); // You can store your selection however you want, outside or inside your objects
+                        if (ImGui::Selectable(items[n], is_selected))
+                            current_item_2 = items[n];
+                        if (is_selected)
+                            ImGui::SetItemDefaultFocus();   // Set the initial focus when opening the combo (scrolling + for keyboard navigation support in the upcoming navigation branch)
+                    }
+                    ImGui::EndCombo();
+                }
+            }
 
             {
                 static char str0[128] = "Hello, world!";