Demo: Using Tabs in Style Editor and Simple Layout example. + Adding missing early out in About and Documents examples.

docs/CHANGELOG.txt

@@ -56,6 +56,7 @@ Other Changes:
   This affects clamping window within the visible area: with this option enabled title bars need to be visible. (#899)
 - Style: Tweaked default value of style.DisplayWindowPadding from (20,20) to (19,19) so the default style as a value
   which is the same as the title bar height.
+- Demo: "Simple Layout" and "Style Editor" are now using tabs.
 - Examples: DirectX10/11/12: Made imgui_impl_dx10/dx11/dx12.cpp link d3dcompiler.lib from the .cpp file
   to ease integration.
 

imgui.h

@@ -533,7 +533,7 @@ namespace ImGui
     // Tab Bars, Tabs
     // [BETA API] API may evolve!
     IMGUI_API bool          BeginTabBar(const char* str_id, ImGuiTabBarFlags flags = 0);        // create and append into a TabBar
-    IMGUI_API void          EndTabBar();
+    IMGUI_API void          EndTabBar();                                                        // only call EndTabBar() if BeginTabBar() returns true!
     IMGUI_API bool          BeginTabItem(const char* label, bool* p_open = NULL, ImGuiTabItemFlags flags = 0);// create a Tab. Returns true if the Tab is selected.
     IMGUI_API void          EndTabItem();                                                       // only call EndTabItem() if BeginTabItem() returns true!
     IMGUI_API void          SetTabItemClosed(const char* tab_or_docked_window_label);           // notify TabBar or Docking system of a closed tab/window ahead (useful to reduce visual flicker on reorderable tab bars). For tab-bar: call after BeginTabBar() and before Tab submissions. Otherwise call with a window name.

imgui_demo.cpp

@@ -2534,7 +2534,11 @@ static void ShowDemoWindowMisc()
 
 void ImGui::ShowAboutWindow(bool* p_open)
 {
-    ImGui::Begin("About Dear ImGui", p_open, ImGuiWindowFlags_AlwaysAutoResize);
+    if (!ImGui::Begin("About Dear ImGui", p_open, ImGuiWindowFlags_AlwaysAutoResize))
+    {
+        ImGui::End();
+        return;
+    }
     ImGui::Text("Dear ImGui %s", ImGui::GetVersion());
     ImGui::Separator();
     ImGui::Text("By Omar Cornut and all dear imgui contributors.");
@@ -2726,20 +2730,13 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
     ImGui::SameLine();
     ShowHelpMarker("Save/Revert in local non-persistent storage. Default Colors definition are not affected. Use \"Export Colors\" below to save them somewhere.");
 
-    if (ImGui::TreeNode("Rendering"))
+    ImGui::Separator();
-    {
-        ImGui::Checkbox("Anti-aliased lines", &style.AntiAliasedLines); ImGui::SameLine(); ShowHelpMarker("When disabling anti-aliasing lines, you'll probably want to disable borders in your style as well.");
-        ImGui::Checkbox("Anti-aliased fill", &style.AntiAliasedFill);
-        ImGui::PushItemWidth(100);
-        ImGui::DragFloat("Curve Tessellation Tolerance", &style.CurveTessellationTol, 0.02f, 0.10f, FLT_MAX, "%.2f", 2.0f);
-        if (style.CurveTessellationTol < 0.10f) style.CurveTessellationTol = 0.10f;
-        ImGui::DragFloat("Global Alpha", &style.Alpha, 0.005f, 0.20f, 1.0f, "%.2f"); // Not exposing zero here so user doesn't "lose" the UI (zero alpha clips all widgets). But application code could have a toggle to switch between zero and non-zero.
-        ImGui::PopItemWidth();
-        ImGui::TreePop();
-    }
 
-    if (ImGui::TreeNode("Settings"))
+    if (ImGui::BeginTabBar("##tabs", ImGuiTabBarFlags_None))
     {
+        if (ImGui::BeginTabItem("Sizes"))
+        {
+            ImGui::Text("Main");
             ImGui::SliderFloat2("WindowPadding", (float*)&style.WindowPadding, 0.0f, 20.0f, "%.0f");
             ImGui::SliderFloat("PopupRounding", &style.PopupRounding, 0.0f, 16.0f, "%.0f");
             ImGui::SliderFloat2("FramePadding", (float*)&style.FramePadding, 0.0f, 20.0f, "%.0f");
@@ -2749,7 +2746,7 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             ImGui::SliderFloat("IndentSpacing", &style.IndentSpacing, 0.0f, 30.0f, "%.0f");
             ImGui::SliderFloat("ScrollbarSize", &style.ScrollbarSize, 1.0f, 20.0f, "%.0f");
             ImGui::SliderFloat("GrabMinSize", &style.GrabMinSize, 1.0f, 20.0f, "%.0f");
-        ImGui::Text("BorderSize");
+            ImGui::Text("Borders");
             ImGui::SliderFloat("WindowBorderSize", &style.WindowBorderSize, 0.0f, 1.0f, "%.0f");
             ImGui::SliderFloat("ChildBorderSize", &style.ChildBorderSize, 0.0f, 1.0f, "%.0f");
             ImGui::SliderFloat("PopupBorderSize", &style.PopupBorderSize, 0.0f, 1.0f, "%.0f");
@@ -2767,10 +2764,10 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             ImGui::SliderFloat2("ButtonTextAlign", (float*)&style.ButtonTextAlign, 0.0f, 1.0f, "%.2f"); ImGui::SameLine(); ShowHelpMarker("Alignment applies when a button is larger than its text content.");
             ImGui::Text("Safe Area Padding"); ImGui::SameLine(); ShowHelpMarker("Adjust if you cannot see the edges of your screen (e.g. on a TV where scaling has not been configured).");
             ImGui::SliderFloat2("DisplaySafeAreaPadding", (float*)&style.DisplaySafeAreaPadding, 0.0f, 30.0f, "%.0f");
-        ImGui::TreePop();
+            ImGui::EndTabItem();
         }
 
-    if (ImGui::TreeNode("Colors"))
+        if (ImGui::BeginTabItem("Colors"))
         {
             static int output_dest = 0;
             static bool output_only_modified = true;
@@ -2786,24 +2783,23 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
                     const ImVec4& col = style.Colors[i];
                     const char* name = ImGui::GetStyleColorName(i);
                     if (!output_only_modified || memcmp(&col, &ref->Colors[i], sizeof(ImVec4)) != 0)
-                    ImGui::LogText("colors[ImGuiCol_%s]%*s= ImVec4(%.2ff, %.2ff, %.2ff, %.2ff);" IM_NEWLINE, name, 23-(int)strlen(name), "", col.x, col.y, col.z, col.w);
+                        ImGui::LogText("colors[ImGuiCol_%s]%*s= ImVec4(%.2ff, %.2ff, %.2ff, %.2ff);" IM_NEWLINE, name, 23 - (int)strlen(name), "", col.x, col.y, col.z, col.w);
                 }
                 ImGui::LogFinish();
             }
             ImGui::SameLine(); ImGui::PushItemWidth(120); ImGui::Combo("##output_type", &output_dest, "To Clipboard\0To TTY\0"); ImGui::PopItemWidth();
             ImGui::SameLine(); ImGui::Checkbox("Only Modified Colors", &output_only_modified);
 
-        ImGui::Text("Tip: Left-click on colored square to open color picker,\nRight-click to open edit options menu.");
-
             static ImGuiTextFilter filter;
-        filter.Draw("Filter colors", 200);
+            filter.Draw("Filter colors", ImGui::GetFontSize() * 16);
 
             static ImGuiColorEditFlags alpha_flags = 0;
             ImGui::RadioButton("Opaque", &alpha_flags, 0); ImGui::SameLine();
             ImGui::RadioButton("Alpha", &alpha_flags, ImGuiColorEditFlags_AlphaPreview); ImGui::SameLine();
-        ImGui::RadioButton("Both", &alpha_flags, ImGuiColorEditFlags_AlphaPreviewHalf);
+            ImGui::RadioButton("Both", &alpha_flags, ImGuiColorEditFlags_AlphaPreviewHalf); ImGui::SameLine();
+            ShowHelpMarker("In the color list:\nLeft-click on colored square to open color picker,\nRight-click to open edit options menu.");
 
-        ImGui::BeginChild("#colors", ImVec2(0, 300), true, ImGuiWindowFlags_AlwaysVerticalScrollbar | ImGuiWindowFlags_AlwaysHorizontalScrollbar | ImGuiWindowFlags_NavFlattened);
+            ImGui::BeginChild("##colors", ImVec2(0, 0), true, ImGuiWindowFlags_AlwaysVerticalScrollbar | ImGuiWindowFlags_AlwaysHorizontalScrollbar | ImGuiWindowFlags_NavFlattened);
             ImGui::PushItemWidth(-160);
             for (int i = 0; i < ImGuiCol_COUNT; i++)
             {
@@ -2826,24 +2822,19 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
             ImGui::PopItemWidth();
             ImGui::EndChild();
 
-        ImGui::TreePop();
+            ImGui::EndTabItem();
         }
 
-    bool fonts_opened = ImGui::TreeNode("Fonts", "Fonts (%d)", ImGui::GetIO().Fonts->Fonts.Size);
+        if (ImGui::BeginTabItem("Fonts"))
-    if (fonts_opened)
         {
             ImFontAtlas* atlas = ImGui::GetIO().Fonts;
-        if (ImGui::TreeNode("Atlas texture", "Atlas texture (%dx%d pixels)", atlas->TexWidth, atlas->TexHeight))
+            ShowHelpMarker("Read FAQ and misc/fonts/README.txt for details on font loading.");
-        {
+            ImGui::PushItemWidth(120);
-            ImGui::Image(atlas->TexID, ImVec2((float)atlas->TexWidth, (float)atlas->TexHeight), ImVec2(0,0), ImVec2(1,1), ImColor(255,255,255,255), ImColor(255,255,255,128));
-            ImGui::TreePop();
-        }
-        ImGui::PushItemWidth(100);
             for (int i = 0; i < atlas->Fonts.Size; i++)
             {
                 ImFont* font = atlas->Fonts[i];
                 ImGui::PushID(font);
-            bool font_details_opened = ImGui::TreeNode(font, "Font %d: \'%s\', %.2f px, %d glyphs", i, font->ConfigData ? font->ConfigData[0].Name : "", font->FontSize, font->Glyphs.Size);
+                bool font_details_opened = ImGui::TreeNode(font, "Font %d: \"%s\"\n%.2f px, %d glyphs, %d file(s)", i, font->ConfigData ? font->ConfigData[0].Name : "", font->FontSize, font->Glyphs.Size, font->ConfigDataCount);
                 ImGui::SameLine(); if (ImGui::SmallButton("Set as default")) ImGui::GetIO().FontDefault = font;
                 if (font_details_opened)
                 {
@@ -2867,7 +2858,7 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
                             int count = 0;
                             for (int n = 0; n < 256; n++)
                                 count += font->FindGlyphNoFallback((ImWchar)(base + n)) ? 1 : 0;
-                        if (count > 0 && ImGui::TreeNode((void*)(intptr_t)base, "U+%04X..U+%04X (%d %s)", base, base+255, count, count > 1 ? "glyphs" : "glyph"))
+                            if (count > 0 && ImGui::TreeNode((void*)(intptr_t)base, "U+%04X..U+%04X (%d %s)", base, base + 255, count, count > 1 ? "glyphs" : "glyph"))
                             {
                                 float cell_size = font->FontSize * 1;
                                 float cell_spacing = style.ItemSpacing.y;
@@ -2877,14 +2868,14 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
                                 {
                                     ImVec2 cell_p1(base_pos.x + (n % 16) * (cell_size + cell_spacing), base_pos.y + (n / 16) * (cell_size + cell_spacing));
                                     ImVec2 cell_p2(cell_p1.x + cell_size, cell_p1.y + cell_size);
-                                const ImFontGlyph* glyph = font->FindGlyphNoFallback((ImWchar)(base+n));
+                                    const ImFontGlyph* glyph = font->FindGlyphNoFallback((ImWchar)(base + n));
-                                draw_list->AddRect(cell_p1, cell_p2, glyph ? IM_COL32(255,255,255,100) : IM_COL32(255,255,255,50));
+                                    draw_list->AddRect(cell_p1, cell_p2, glyph ? IM_COL32(255, 255, 255, 100) : IM_COL32(255, 255, 255, 50));
                                     if (glyph)
-                                    font->RenderChar(draw_list, cell_size, cell_p1, ImGui::GetColorU32(ImGuiCol_Text), (ImWchar)(base+n)); // We use ImFont::RenderChar as a shortcut because we don't have UTF-8 conversion functions available to generate a string.
+                                        font->RenderChar(draw_list, cell_size, cell_p1, ImGui::GetColorU32(ImGuiCol_Text), (ImWchar)(base + n)); // We use ImFont::RenderChar as a shortcut because we don't have UTF-8 conversion functions available to generate a string.
                                     if (glyph && ImGui::IsMouseHoveringRect(cell_p1, cell_p2))
                                     {
                                         ImGui::BeginTooltip();
-                                    ImGui::Text("Codepoint: U+%04X", base+n);
+                                        ImGui::Text("Codepoint: U+%04X", base + n);
                                         ImGui::Separator();
                                         ImGui::Text("AdvanceX: %.1f", glyph->AdvanceX);
                                         ImGui::Text("Pos: (%.2f,%.2f)->(%.2f,%.2f)", glyph->X0, glyph->Y0, glyph->X1, glyph->Y1);
@@ -2902,12 +2893,35 @@ void ImGui::ShowStyleEditor(ImGuiStyle* ref)
                 }
                 ImGui::PopID();
             }
+            if (ImGui::TreeNode("Atlas texture", "Atlas texture (%dx%d pixels)", atlas->TexWidth, atlas->TexHeight))
+            {
+                ImGui::Image(atlas->TexID, ImVec2((float)atlas->TexWidth, (float)atlas->TexHeight), ImVec2(0, 0), ImVec2(1, 1), ImColor(255, 255, 255, 255), ImColor(255, 255, 255, 128));
+                ImGui::TreePop();
+            }
+
             static float window_scale = 1.0f;
-        ImGui::DragFloat("this window scale", &window_scale, 0.005f, 0.3f, 2.0f, "%.1f");              // scale only this window
+            if (ImGui::DragFloat("this window scale", &window_scale, 0.005f, 0.3f, 2.0f, "%.1f"))           // scale only this window
+                ImGui::SetWindowFontScale(window_scale);
             ImGui::DragFloat("global scale", &ImGui::GetIO().FontGlobalScale, 0.005f, 0.3f, 2.0f, "%.1f");  // scale everything
             ImGui::PopItemWidth();
-        ImGui::SetWindowFontScale(window_scale);
+
-        ImGui::TreePop();
+            ImGui::EndTabItem();
+        }
+
+        if (ImGui::BeginTabItem("Rendering"))
+        {
+            ImGui::Checkbox("Anti-aliased lines", &style.AntiAliasedLines); ImGui::SameLine(); ShowHelpMarker("When disabling anti-aliasing lines, you'll probably want to disable borders in your style as well.");
+            ImGui::Checkbox("Anti-aliased fill", &style.AntiAliasedFill);
+            ImGui::PushItemWidth(100);
+            ImGui::DragFloat("Curve Tessellation Tolerance", &style.CurveTessellationTol, 0.02f, 0.10f, FLT_MAX, "%.2f", 2.0f);
+            if (style.CurveTessellationTol < 0.10f) style.CurveTessellationTol = 0.10f;
+            ImGui::DragFloat("Global Alpha", &style.Alpha, 0.005f, 0.20f, 1.0f, "%.2f"); // Not exposing zero here so user doesn't "lose" the UI (zero alpha clips all widgets). But application code could have a toggle to switch between zero and non-zero.
+            ImGui::PopItemWidth();
+
+            ImGui::EndTabItem();
+        }
+
+        ImGui::EndTabBar();
     }
 
     ImGui::PopItemWidth();
@@ -3447,7 +3461,20 @@ static void ShowExampleAppLayout(bool* p_open)
             ImGui::BeginChild("item view", ImVec2(0, -ImGui::GetFrameHeightWithSpacing())); // Leave room for 1 line below us
                 ImGui::Text("MyObject: %d", selected);
                 ImGui::Separator();
+                if (ImGui::BeginTabBar("##Tabs", ImGuiTabBarFlags_None))
+                {
+                    if (ImGui::BeginTabItem("Description"))
+                    {
                         ImGui::TextWrapped("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. ");
+                        ImGui::EndTabItem();
+                    }
+                    if (ImGui::BeginTabItem("Details"))
+                    {
+                        ImGui::Text("ID: 0123456789");
+                        ImGui::EndTabItem();
+                    }
+                    ImGui::EndTabBar();
+                }
             ImGui::EndChild();
             if (ImGui::Button("Revert")) {}
             ImGui::SameLine();
@@ -3935,7 +3962,11 @@ void ShowExampleAppDocuments(bool* p_open)
 {
     static ExampleAppDocuments app;
 
-    ImGui::Begin("Examples: Documents", p_open, ImGuiWindowFlags_MenuBar);
+    if (!ImGui::Begin("Examples: Documents", p_open, ImGuiWindowFlags_MenuBar))
+    {
+        ImGui::End();
+        return;
+    }
 
     // Options
     static bool opt_reorderable = true;