Demo: Added Auto-Scroll option in Log/Console. Comments. Removed some ImColor() uses.

docs/CHANGELOG.txt

@@ -76,6 +76,7 @@ Other Changes:
 - ImFontAtlas: FreeType: Added support for imgui allocators + custom FreeType only SetAllocatorFunctions. (#2285) [@Vuhdo]
 - ImFontAtlas: FreeType: Fixed using imgui_freetype.cpp in unity builds. (#2302)
 - Demo: Fixed "Log" demo not initializing properly, leading to the first line not showing before a Clear. (#2318) [@bluescan]
+- Demo: Added "Auto-scroll" option in Log/Console demos. (#2300) [@nicolasnoble, @ocornut]
 - Examples: Metal, OpenGL2, OpenGL3: Fixed offsetting of clipping rectangle with ImDrawData::DisplayPos != (0,0) when
   the display frame-buffer scale scale is not (1,1). While this doesn't make a difference when using master branch,
   this is effectively fixing support for multi-viewport with Mac Retina Displays on those examples. (#2306) [@rasky, @ocornut]

imgui.cpp

@@ -9301,7 +9301,7 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             if (draw_list == ImGui::GetWindowDrawList())
             {
                 ImGui::SameLine();
-                ImGui::TextColored(ImColor(255,100,100), "CURRENTLY APPENDING"); // Can't display stats for active draw list! (we don't have the data double-buffered)
+                ImGui::TextColored(ImVec4(1.0f,0.4f,0.4f,1.0f), "CURRENTLY APPENDING"); // Can't display stats for active draw list! (we don't have the data double-buffered)
                 if (node_open) ImGui::TreePop();
                 return;
             }

imgui_demo.cpp

@@ -1005,7 +1005,7 @@ static void ShowDemoWindowWidgets()
 
     if (ImGui::TreeNode("Color/Picker Widgets"))
     {
-        static ImVec4 color = ImColor(114, 144, 154, 200);
+        static ImVec4 color = ImVec4(114.0f/255.0f, 144.0f/255.0f, 154.0f/255.0f, 200.0f/255.0f);
 
         static bool alpha_preview = true;
         static bool alpha_half_preview = false;
@@ -3095,10 +3095,12 @@ struct ExampleAppConsole
 {
     char                  InputBuf[256];
     ImVector<char*>       Items;
-    bool                  ScrollToBottom;
+    ImVector<const char*> Commands;
     ImVector<char*>       History;
     int                   HistoryPos;    // -1: new line, 0..History.Size-1 browsing history.
-    ImVector<const char*> Commands;
+    ImGuiTextFilter       Filter;
+    bool                  AutoScroll;
+    bool                  ScrollToBottom;
 
     ExampleAppConsole()
     {
@@ -3109,6 +3111,8 @@ struct ExampleAppConsole
         Commands.push_back("HISTORY");
         Commands.push_back("CLEAR");
         Commands.push_back("CLASSIFY");  // "classify" is only here to provide an example of "C"+[tab] completing to "CL" and displaying matches.
+        AutoScroll = true;
+        ScrollToBottom = true;
         AddLog("Welcome to Dear ImGui!");
     }
     ~ExampleAppConsole()
@@ -3142,7 +3146,8 @@ struct ExampleAppConsole
         buf[IM_ARRAYSIZE(buf)-1] = 0;
         va_end(args);
         Items.push_back(Strdup(buf));
-        ScrollToBottom = true;
+        if (AutoScroll)
+            ScrollToBottom = true;
     }
 
     void    Draw(const char* title, bool* p_open)
@@ -3168,7 +3173,7 @@ struct ExampleAppConsole
 
         // TODO: display items starting from the bottom
 
-        if (ImGui::SmallButton("Add Dummy Text")) { AddLog("%d some text", Items.Size); AddLog("some more text"); AddLog("display very important message here!"); } ImGui::SameLine();
+        if (ImGui::SmallButton("Add Dummy Text"))  { AddLog("%d some text", Items.Size); AddLog("some more text"); AddLog("display very important message here!"); } ImGui::SameLine();
         if (ImGui::SmallButton("Add Dummy Error")) { AddLog("[error] something went wrong"); } ImGui::SameLine();
         if (ImGui::SmallButton("Clear")) { ClearLog(); } ImGui::SameLine();
         bool copy_to_clipboard = ImGui::SmallButton("Copy"); ImGui::SameLine();
@@ -3177,10 +3182,20 @@ struct ExampleAppConsole
 
         ImGui::Separator();
 
-        ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(0,0));
-        static ImGuiTextFilter filter;
-        filter.Draw("Filter (\"incl,-excl\") (\"error\")", 180);
-        ImGui::PopStyleVar();
+        // Options menu
+        if (ImGui::BeginPopup("Options"))
+        {
+            if (ImGui::Checkbox("Auto-scroll", &AutoScroll))
+                if (AutoScroll)
+                    ScrollToBottom = true;
+            ImGui::EndPopup();
+        }
+
+        // Options, Filter
+        if (ImGui::Button("Options"))
+            ImGui::OpenPopup("Options");
+        ImGui::SameLine();
+        Filter.Draw("Filter (\"incl,-excl\") (\"error\")", 180);
         ImGui::Separator();
 
         const float footer_height_to_reserve = ImGui::GetStyle().ItemSpacing.y + ImGui::GetFrameHeightWithSpacing(); // 1 separator, 1 input text
@@ -3205,18 +3220,19 @@ struct ExampleAppConsole
         ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, ImVec2(4,1)); // Tighten spacing
         if (copy_to_clipboard)
             ImGui::LogToClipboard();
-        ImVec4 col_default_text = ImGui::GetStyleColorVec4(ImGuiCol_Text);
         for (int i = 0; i < Items.Size; i++)
         {
             const char* item = Items[i];
-            if (!filter.PassFilter(item))
+            if (!Filter.PassFilter(item))
                 continue;
-            ImVec4 col = col_default_text;
-            if (strstr(item, "[error]")) col = ImColor(1.0f,0.4f,0.4f,1.0f);
-            else if (strncmp(item, "# ", 2) == 0) col = ImColor(1.0f,0.78f,0.58f,1.0f);
-            ImGui::PushStyleColor(ImGuiCol_Text, col);
+
+            // Normally you would store more information in your item (e.g. make Items[] an array of structure, store color/type etc.)
+            bool pop_color = false;
+            if (strstr(item, "[error]"))            { ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.0f, 0.4f, 0.4f, 1.0f)); pop_color = true; }
+            else if (strncmp(item, "# ", 2) == 0)   { ImGui::PushStyleColor(ImGuiCol_Text, ImVec4(1.0f, 0.8f, 0.6f, 1.0f)); pop_color = true; }
             ImGui::TextUnformatted(item);
-            ImGui::PopStyleColor();
+            if (pop_color)
+                ImGui::PopStyleColor();
         }
         if (copy_to_clipboard)
             ImGui::LogFinish();
@@ -3283,6 +3299,9 @@ struct ExampleAppConsole
         {
             AddLog("Unknown command: '%s'\n", command_line);
         }
+
+        // On commad input, we scroll to bottom even if AutoScroll==false
+        ScrollToBottom = true;
     }
 
     static int TextEditCallbackStub(ImGuiInputTextCallbackData* data) // In C++11 you are better off using lambdas for this sort of forwarding callbacks
@@ -3411,10 +3430,12 @@ struct ExampleAppLog
     ImGuiTextBuffer     Buf;
     ImGuiTextFilter     Filter;
     ImVector<int>       LineOffsets;        // Index to lines offset. We maintain this with AddLog() calls, allowing us to have a random access on lines
+    bool                AutoScroll;
     bool                ScrollToBottom;
 
     ExampleAppLog()
     {
+        AutoScroll = true;
         ScrollToBottom = false;
         Clear();
     }
@@ -3436,7 +3457,8 @@ struct ExampleAppLog
         for (int new_size = Buf.size(); old_size < new_size; old_size++)
             if (Buf[old_size] == '\n')
                 LineOffsets.push_back(old_size + 1);
-        ScrollToBottom = true;
+        if (AutoScroll)
+            ScrollToBottom = true;
     }
 
     void    Draw(const char* title, bool* p_open = NULL)
@@ -3446,13 +3468,31 @@ struct ExampleAppLog
             ImGui::End();
             return;
         }
-        if (ImGui::Button("Clear")) Clear();
+
+        // Options menu
+        if (ImGui::BeginPopup("Options"))
+        {
+            if (ImGui::Checkbox("Auto-scroll", &AutoScroll))
+                if (AutoScroll)
+                    ScrollToBottom = true;
+            ImGui::EndPopup();
+        }
+
+        // Main window
+        if (ImGui::Button("Options"))
+            ImGui::OpenPopup("Options");
+        ImGui::SameLine();
+        bool clear = ImGui::Button("Clear");
         ImGui::SameLine();
         bool copy = ImGui::Button("Copy");
         ImGui::SameLine();
         Filter.Draw("Filter", -100.0f);
+
         ImGui::Separator();
         ImGui::BeginChild("scrolling", ImVec2(0,0), false, ImGuiWindowFlags_HorizontalScrollbar);
+
+        if (clear)
+            Clear();
         if (copy)
             ImGui::LogToClipboard();
 
@@ -3461,6 +3501,10 @@ struct ExampleAppLog
         const char* buf_end = Buf.end();
         if (Filter.IsActive())
         {
+            // In this example we don't use the clipper when Filter is enabled.
+            // This is because we don't have a random access on the result on our filter.
+            // A real application processing logs with ten of thousands of entries may want to store the result of search/filter.
+            // especially if the filtering function is not trivial (e.g. reg-exp).
             for (int line_no = 0; line_no < LineOffsets.Size; line_no++)
             {
                 const char* line_start = buf + LineOffsets[line_no];
@@ -3508,11 +3552,12 @@ static void ShowExampleAppLog(bool* p_open)
 {
     static ExampleAppLog log;
 
-    // For the demo: add a debug button before the normal log window contents
+    // For the demo: add a debug button _BEFORE_ the normal log window contents
     // We take advantage of the fact that multiple calls to Begin()/End() are appending to the same window.
+    // Most of the contents of the window will be added by the log.Draw() call.
     ImGui::SetNextWindowSize(ImVec2(500, 400), ImGuiCond_FirstUseEver);
     ImGui::Begin("Example: Log", p_open);
-    if (ImGui::SmallButton("Add 5 entries"))
+    if (ImGui::SmallButton("[Debug] Add 5 entries"))
     {
         static int counter = 0;
         for (int n = 0; n < 5; n++)