From 5fed6bdc72c73f4bf3ac8892778846ff1fdce421 Mon Sep 17 00:00:00 2001 From: ocornut Date: Thu, 15 Apr 2021 15:53:50 +0200 Subject: [PATCH] Demo: Improved popups demo and comments. --- docs/CHANGELOG.txt | 1 + imgui.cpp | 19 ++++++-- imgui.h | 2 +- imgui_demo.cpp | 106 ++++++++++++++++++++++++++++++--------------- 4 files changed, 89 insertions(+), 39 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index bcfa40f98..104cccaff 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -54,6 +54,7 @@ Other Changes: - LabelText: Fixed clipping of multi-line value text when label is single-line. (#4004) - LabelText: Fixed vertical alignment of single-line value text when label is multi-line. (#4004) - Popups: Added 'OpenPopup(ImGuiID id)' overload to facilitate calling from nested stacks. (#3993, #331) [@zlash] +- Demo: Improved popups demo and comments. - Backends: SDL: Rework global mouse pos availability check listing supported platforms explicitly, effectively fixing mouse access on Raspberry Pi. (#2837, #3950) [@lethal-guitar, @hinxx] - Backends: Win32: Clearing keyboard down array when losing focus (WM_KILLFOCUS). (#2062, #3532, #3961) diff --git a/imgui.cpp b/imgui.cpp index 7a1460fb8..6ce2b950d 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -8363,10 +8363,21 @@ void ImGui::OpenPopupOnItemClick(const char* str_id, ImGuiPopupFlags popup_flags } // This is a helper to handle the simplest case of associating one named popup to one given widget. -// - You can pass a NULL str_id to use the identifier of the last item. -// - You may want to handle this on user side if you have specific needs (e.g. tweaking IsItemHovered() parameters). -// - This is essentially the same as calling OpenPopupOnItemClick() + BeginPopup() but written to avoid -// computing the ID twice because BeginPopupContextXXX functions may be called very frequently. +// - To create a popup associated to the last item, you generally want to pass a NULL value to str_id. +// - To create a popup with a specific identifier, pass it in str_id. +// - This is useful when using using BeginPopupContextItem() on an item which doesn't have an identifier, e.g. a Text() call. +// - This is useful when multiple code locations may want to manipulate/open the same popup, given an explicit id. +// - You may want to handle the whole on user side if you have specific needs (e.g. tweaking IsItemHovered() parameters). +// This is essentially the same as: +// id = str_id ? GetID(str_id) : GetItemID(); +// OpenPopupOnItemClick(str_id); +// return BeginPopup(id); +// Which is essentially the same as: +// id = str_id ? GetID(str_id) : GetItemID(); +// if (IsItemHovered() && IsMouseReleased(ImGuiMouseButton_Right)) +// OpenPopup(id); +// return BeginPopup(id); +// The main difference being that this is tweaked to avoid computing the ID twice. bool ImGui::BeginPopupContextItem(const char* str_id, ImGuiPopupFlags popup_flags) { ImGuiWindow* window = GImGui->CurrentWindow; diff --git a/imgui.h b/imgui.h index 9e1bb56f5..1caf93230 100644 --- a/imgui.h +++ b/imgui.h @@ -661,7 +661,7 @@ namespace ImGui // - They are convenient to easily create context menus, hence the name. // - IMPORTANT: Notice that BeginPopupContextXXX takes ImGuiPopupFlags just like OpenPopup() and unlike BeginPopup(). For full consistency, we may add ImGuiWindowFlags to the BeginPopupContextXXX functions in the future. // - IMPORTANT: we exceptionally default their flags to 1 (== ImGuiPopupFlags_MouseButtonRight) for backward compatibility with older API taking 'int mouse_button = 1' parameter, so if you add other flags remember to re-add the ImGuiPopupFlags_MouseButtonRight. - IMGUI_API bool BeginPopupContextItem(const char* str_id = NULL, ImGuiPopupFlags popup_flags = 1); // open+begin popup when clicked on last item. if you can pass a NULL str_id only if the previous item had an id. If you want to use that on a non-interactive item such as Text() you need to pass in an explicit ID here. read comments in .cpp! + IMGUI_API bool BeginPopupContextItem(const char* str_id = NULL, ImGuiPopupFlags popup_flags = 1); // open+begin popup when clicked on last item. Use str_id==NULL to associate the popup to previous item. If you want to use that on a non-interactive item such as Text() you need to pass in an explicit ID here. read comments in .cpp! IMGUI_API bool BeginPopupContextWindow(const char* str_id = NULL, ImGuiPopupFlags popup_flags = 1);// open+begin popup when clicked on current window. IMGUI_API bool BeginPopupContextVoid(const char* str_id = NULL, ImGuiPopupFlags popup_flags = 1); // open+begin popup when clicked in void (where there are no windows). // Popups: query functions diff --git a/imgui_demo.cpp b/imgui_demo.cpp index 5ccee4f7f..6cf6848eb 100644 --- a/imgui_demo.cpp +++ b/imgui_demo.cpp @@ -3192,46 +3192,84 @@ static void ShowDemoWindowPopups() if (ImGui::TreeNode("Context menus")) { + HelpMarker("\"Context\" functions are simple helpers to associate a Popup to a given Item or Window identifier."); + // BeginPopupContextItem() is a helper to provide common/simple popup behavior of essentially doing: - // if (IsItemHovered() && IsMouseReleased(ImGuiMouseButton_Right)) - // OpenPopup(id); - // return BeginPopup(id); - // For more advanced uses you may want to replicate and customize this code. - // See details in BeginPopupContextItem(). - static float value = 0.5f; - ImGui::Text("Value = %.3f (<-- right-click here)", value); - if (ImGui::BeginPopupContextItem("item context menu")) + // if (id == 0) + // id = GetItemID(); // Use last item id + // if (IsItemHovered() && IsMouseReleased(ImGuiMouseButton_Right)) + // OpenPopup(id); + // return BeginPopup(id); + // For advanced advanced uses you may want to replicate and customize this code. + // See more details in BeginPopupContextItem(). + + // Example 1 + // When used after an item that has an ID (e.g. Button), we can skip providing an ID to BeginPopupContextItem(), + // and BeginPopupContextItem() will use the last item ID as the popup ID. { - if (ImGui::Selectable("Set to zero")) value = 0.0f; - if (ImGui::Selectable("Set to PI")) value = 3.1415f; - ImGui::SetNextItemWidth(-FLT_MIN); - ImGui::DragFloat("##Value", &value, 0.1f, 0.0f, 0.0f); - ImGui::EndPopup(); + const char* names[5] = { "Label1", "Label2", "Label3", "Label4", "Label5" }; + for (int n = 0; n < 5; n++) + { + ImGui::Selectable(names[n]); + if (ImGui::BeginPopupContextItem()) // <-- use last item id as popup id + { + ImGui::Text("This a popup for \"%s\"!", names[n]); + if (ImGui::Button("Close")) + ImGui::CloseCurrentPopup(); + ImGui::EndPopup(); + } + if (ImGui::IsItemHovered()) + ImGui::SetTooltip("Right-click to open popup"); + } } - // We can also use OpenPopupOnItemClick() which is the same as BeginPopupContextItem() but without the - // Begin() call. So here we will make it that clicking on the text field with the right mouse button (1) - // will toggle the visibility of the popup above. - ImGui::Text("(You can also right-click me to open the same popup as above.)"); - ImGui::OpenPopupOnItemClick("item context menu", 1); - - // When used after an item that has an ID (e.g.Button), we can skip providing an ID to BeginPopupContextItem(). - // BeginPopupContextItem() will use the last item ID as the popup ID. - // In addition here, we want to include your editable label inside the button label. - // We use the ### operator to override the ID (read FAQ about ID for details) - static char name[32] = "Label1"; - char buf[64]; - sprintf(buf, "Button: %s###Button", name); // ### operator override ID ignoring the preceding label - ImGui::Button(buf); - if (ImGui::BeginPopupContextItem()) + // Example 2 + // Popup on a Text() element which doesn't have an identifier: we need to provide an identifier to BeginPopupContextItem(). + // Using an explicit identifier is also convenient if you want to activate the popups from different locations. { - ImGui::Text("Edit name:"); - ImGui::InputText("##edit", name, IM_ARRAYSIZE(name)); - if (ImGui::Button("Close")) - ImGui::CloseCurrentPopup(); - ImGui::EndPopup(); + HelpMarker("Text() elements don't have stable identifiers so we need to provide one."); + static float value = 0.5f; + ImGui::Text("Value = %.3f <-- (1) right-click this value", value); + if (ImGui::BeginPopupContextItem("my popup")) + { + if (ImGui::Selectable("Set to zero")) value = 0.0f; + if (ImGui::Selectable("Set to PI")) value = 3.1415f; + ImGui::SetNextItemWidth(-FLT_MIN); + ImGui::DragFloat("##Value", &value, 0.1f, 0.0f, 0.0f); + ImGui::EndPopup(); + } + + // We can also use OpenPopupOnItemClick() to toggle the visibility of a given popup. + // Here we make it that right-clicking this other text element opens the same popup as above. + // The popup itself will be submitted by the code above. + ImGui::Text("(2) Or right-click this text"); + ImGui::OpenPopupOnItemClick("my popup", ImGuiPopupFlags_MouseButtonRight); + + // Back to square one: manually open the same popup. + if (ImGui::Button("(3) Or click this button")) + ImGui::OpenPopup("my popup"); + } + + // Example 3 + // When using BeginPopupContextItem() with an implicit identifier (NULL == use last item ID), + // we need to make sure your item identifier is stable. + // In this example we showcase altering the item label while preserving its identifier, using the ### operator (see FAQ). + { + HelpMarker("Showcase using a popup ID linked to item ID, with the item having a changing label + stable ID using the ### operator."); + static char name[32] = "Label1"; + char buf[64]; + sprintf(buf, "Button: %s###Button", name); // ### operator override ID ignoring the preceding label + ImGui::Button(buf); + if (ImGui::BeginPopupContextItem()) + { + ImGui::Text("Edit name:"); + ImGui::InputText("##edit", name, IM_ARRAYSIZE(name)); + if (ImGui::Button("Close")) + ImGui::CloseCurrentPopup(); + ImGui::EndPopup(); + } + ImGui::SameLine(); ImGui::Text("(<-- right-click here)"); } - ImGui::SameLine(); ImGui::Text("(<-- right-click here)"); ImGui::TreePop(); }