diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index 5b33b11d..35265e30 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -36,12 +36,13 @@ HOW TO UPDATE? Breaking Changes: -- Removed unncessary ID (first arg) of ImFontAtlas::AddCustomRectRegular() function. Please +- Removed unnecessary ID (first arg) of ImFontAtlas::AddCustomRectRegular() function. Please note that this is a Beta api and will likely be reworked to support multi-monitor multi-DPI. - Renamed OpenPopupOnItemClick() to OpenPopupContextItem(). Kept inline redirection function (will obsolete). - Removed BeginPopupContextWindow(const char*, int mouse_button, bool also_over_items) in favor of BeginPopupContextWindow(const char*, ImGuiPopupFlags flags) with ImGuiPopupFlags_NoOverItems. -- Removed CalcItemRectClosestPoint() entry point which was made obsolete and asserting in December 2017. + Kept inline redirection function (will obsolete). +- Removed obsoleted CalcItemRectClosestPoint() entry point (has been asserting since December 2017). Other Changes: diff --git a/docs/FAQ.md b/docs/FAQ.md index 55e7ebeb..adce4d40 100644 --- a/docs/FAQ.md +++ b/docs/FAQ.md @@ -23,7 +23,7 @@ or view this file with any Markdown viewer. | [I integrated Dear ImGui in my engine and some elements are clipping or disappearing when I move windows around..](#q-i-integrated-dear-imgui-in-my-engine-and-some-elements-are-clipping-or-disappearing-when-i-move-windows-around) | | [I integrated Dear ImGui in my engine and some elements are displaying outside their expected windows boundaries..](#q-i-integrated-dear-imgui-in-my-engine-and-some-elements-are-displaying-outside-their-expected-windows-boundaries) | | **Q&A: Usage** | -| **[Why are multiple widgets reacting when I interact with a single one?
How can I have multiple widgets with the same label or with an empty label?](#q-why-are-multiple-widgets-reacting-when-i-interact-with-a-single-one-q-how-can-i-have-multiple-widgets-with-the-same-label-or-with-an-empty-label)** | +| **[How can I have widgets with an empty label?
How can I have multiple widgets with the same label?
Why are multiple widgets reacting when I interact with one?](#q-how-can-i-have-widgets-with-an-empty-label)** | | [How can I display an image? What is ImTextureID, how does it work?](#q-how-can-i-display-an-image-what-is-imtextureid-how-does-it-work)| | [How can I use my own math types instead of ImVec2/ImVec4?](#q-how-can-i-use-my-own-math-types-instead-of-imvec2imvec4) | | [How can I interact with standard C++ types (such as std::string and std::vector)?](#q-how-can-i-interact-with-standard-c-types-such-as-stdstring-and-stdvector) | @@ -173,7 +173,9 @@ Refer to rendering back-ends in the [examples/](https://github.com/ocornut/imgui # Q&A: Usage -### Q: Why are multiple widgets reacting when I interact with a single one?
Q: How can I have multiple widgets with the same label or with an empty label? +### Q: How can I have widgets with an empty label? +### Q: How can I have multiple widgets with the same label? +### Q: Why are multiple widgets reacting when I interact with one? A primer on labels and the ID Stack... @@ -295,11 +297,12 @@ if (TreeNode("node")) // <-- this function call will do a PushID() for you (unl TreePop(); } ``` -- When working with trees, ID are used to preserve the open/close state of each tree node. + +When working with trees, ID are used to preserve the open/close state of each tree node. Depending on your use cases you may want to use strings, indices or pointers as ID. -e.g. when following a single pointer that may change over time, using a static string as ID +- e.g. when following a single pointer that may change over time, using a static string as ID will preserve your node open/closed state when the targeted object change. -e.g. when displaying a list of objects, using indices or pointers as ID will preserve the +- e.g. when displaying a list of objects, using indices or pointers as ID will preserve the node open/closed state differently. See what makes more sense in your situation! ##### [Return to Index](#index) diff --git a/imgui.cpp b/imgui.cpp index 07c5ea4a..a4ec7178 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -601,7 +601,10 @@ CODE FREQUENTLY ASKED QUESTIONS (FAQ) ================================ - Read all answers online: https://www.dearimgui.org/faq, or in docs/FAQ.md (with a Markdown viewer) + Read all answers online: + https://www.dearimgui.org/faq or https://github.com/ocornut/imgui/blob/master/docs/FAQ.md (same url) + Read all answers locally (with a text editor or ideally a Markdown viewer): + docs/FAQ.md Some answers are copied down here to facilitate searching in code. Q&A: Basics @@ -640,130 +643,15 @@ CODE Q: I integrated Dear ImGui in my engine and little squares are showing instead of text.. Q: I integrated Dear ImGui in my engine and some elements are clipping or disappearing when I move windows around.. Q: I integrated Dear ImGui in my engine and some elements are displaying outside their expected windows boundaries.. ->> See https://www.dearimgui.org/faq + >> See https://www.dearimgui.org/faq Q&A: Usage ---------- - Q: Why are multiple widgets reacting when I interact with a single one? - Q: How can I have multiple widgets with the same label or with an empty label? - A: A primer on labels and the ID Stack... - - Dear ImGui internally need to uniquely identify UI elements. - Elements that are typically not clickable (such as calls to the Text functions) don't need an ID. - Interactive widgets (such as calls to Button buttons) need a unique ID. - Unique ID are used internally to track active widgets and occasionally associate state to widgets. - Unique ID are implicitly built from the hash of multiple elements that identify the "path" to the UI element. - - - Unique ID are often derived from a string label: - - Button("OK"); // Label = "OK", ID = hash of (..., "OK") - Button("Cancel"); // Label = "Cancel", ID = hash of (..., "Cancel") - - - ID are uniquely scoped within windows, tree nodes, etc. which all pushes to the ID stack. Having - two buttons labeled "OK" in different windows or different tree locations is fine. - We used "..." above to signify whatever was already pushed to the ID stack previously: - - Begin("MyWindow"); - Button("OK"); // Label = "OK", ID = hash of ("MyWindow", "OK") - End(); - Begin("MyOtherWindow"); - Button("OK"); // Label = "OK", ID = hash of ("MyOtherWindow", "OK") - End(); - - - If you have a same ID twice in the same location, you'll have a conflict: - - Button("OK"); - Button("OK"); // ID collision! Interacting with either button will trigger the first one. - - Fear not! this is easy to solve and there are many ways to solve it! - - - Solving ID conflict in a simple/local context: - When passing a label you can optionally specify extra ID information within string itself. - Use "##" to pass a complement to the ID that won't be visible to the end-user. - This helps solving the simple collision cases when you know e.g. at compilation time which items - are going to be created: - - Begin("MyWindow"); - Button("Play"); // Label = "Play", ID = hash of ("MyWindow", "Play") - Button("Play##foo1"); // Label = "Play", ID = hash of ("MyWindow", "Play##foo1") // Different from above - Button("Play##foo2"); // Label = "Play", ID = hash of ("MyWindow", "Play##foo2") // Different from above - End(); - - - If you want to completely hide the label, but still need an ID: - - Checkbox("##On", &b); // Label = "", ID = hash of (..., "##On") // No visible label, just a checkbox! - - - Occasionally/rarely you might want change a label while preserving a constant ID. This allows - you to animate labels. For example you may want to include varying information in a window title bar, - but windows are uniquely identified by their ID. Use "###" to pass a label that isn't part of ID: - - Button("Hello###ID"); // Label = "Hello", ID = hash of (..., "###ID") - Button("World###ID"); // Label = "World", ID = hash of (..., "###ID") // Same as above, even though the label looks different - - sprintf(buf, "My game (%f FPS)###MyGame", fps); - Begin(buf); // Variable title, ID = hash of "MyGame" - - - Solving ID conflict in a more general manner: - Use PushID() / PopID() to create scopes and manipulate the ID stack, as to avoid ID conflicts - within the same window. This is the most convenient way of distinguishing ID when iterating and - creating many UI elements programmatically. - You can push a pointer, a string or an integer value into the ID stack. - Remember that ID are formed from the concatenation of _everything_ pushed into the ID stack. - At each level of the stack we store the seed used for items at this level of the ID stack. - - Begin("Window"); - for (int i = 0; i < 100; i++) - { - PushID(i); // Push i to the id tack - Button("Click"); // Label = "Click", ID = hash of ("Window", i, "Click") - PopID(); - } - for (int i = 0; i < 100; i++) - { - MyObject* obj = Objects[i]; - PushID(obj); - Button("Click"); // Label = "Click", ID = hash of ("Window", obj pointer, "Click") - PopID(); - } - for (int i = 0; i < 100; i++) - { - MyObject* obj = Objects[i]; - PushID(obj->Name); - Button("Click"); // Label = "Click", ID = hash of ("Window", obj->Name, "Click") - PopID(); - } - End(); - - - You can stack multiple prefixes into the ID stack: - - Button("Click"); // Label = "Click", ID = hash of (..., "Click") - PushID("node"); - Button("Click"); // Label = "Click", ID = hash of (..., "node", "Click") - PushID(my_ptr); - Button("Click"); // Label = "Click", ID = hash of (..., "node", my_ptr, "Click") - PopID(); - PopID(); - - - Tree nodes implicitly creates a scope for you by calling PushID(). - - Button("Click"); // Label = "Click", ID = hash of (..., "Click") - if (TreeNode("node")) // <-- this function call will do a PushID() for you (unless instructed not to, with a special flag) - { - Button("Click"); // Label = "Click", ID = hash of (..., "node", "Click") - TreePop(); - } - - - When working with trees, ID are used to preserve the open/close state of each tree node. - Depending on your use cases you may want to use strings, indices or pointers as ID. - e.g. when following a single pointer that may change over time, using a static string as ID - will preserve your node open/closed state when the targeted object change. - e.g. when displaying a list of objects, using indices or pointers as ID will preserve the - node open/closed state differently. See what makes more sense in your situation! - + Q: How can I have widgets with an empty label? + Q: How can I have multiple widgets with the same label? + Q: Why are multiple widgets reacting when I interact with one? Q: How can I display an image? What is ImTextureID, how does it works? - >> See https://www.dearimgui.org/faq and https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples - Q: How can I use my own math types instead of ImVec2/ImVec4? Q: How can I interact with standard C++ types (such as std::string and std::vector)? Q: How can I display custom shapes? (using low-level ImDrawList API)