Platform: use StringView in *Application::Text*Event.

Which allows to get rid of a now-unneeded ArrayView include in the
header. Also, now that we're returning a StringView, it's useful to
have the view always null-terminated. In SDL2 and Emscripten it was
already like that, GLFW needed a minor change.

src/Magnum/Platform/EmscriptenApplication.cpp

@@ -631,11 +631,11 @@ void EmscriptenApplication::setupCallbacks(bool resizable) {
     emscripten_set_keydown_callback(keyboardListeningElement, this, false,
         ([](int, const EmscriptenKeyboardEvent* event, void* userData) -> Int {
             EmscriptenApplication& app = *static_cast<EmscriptenApplication*>(userData);
-            const std::size_t keyLen = std::strlen(event->key);
+            const Containers::StringView key = event->key;
             /* If the key name is a single letter or a start of an UTF-8
-               sequence, pass it to the text input even tas well */
-            if(app.isTextInputActive() && (std::strlen(event->key) == 1 || (std::strlen(event->key) >= 1 && UnsignedByte(event->key[0]) > 127))) {
-                TextInputEvent e{*event, {event->key, keyLen}};
+               sequence, pass it to the text input event as well */
+            if(app.isTextInputActive() && key.size() == 1 || (key.size() >= 1 && UnsignedByte(key[0]) > 127)) {
+                TextInputEvent e{*event, key};
                 app.textInputEvent(e);
                 return e.isAccepted();
             }

src/Magnum/Platform/EmscriptenApplication.h

@@ -34,7 +34,6 @@
  */
 #endif
 
-#include <Corrade/Containers/ArrayView.h>
 /* Needed by the MAGNUM_EMSCRIPTENAPPLICATION_MAIN() macro */
 /** @todo use an Optional */
 #include <Corrade/Containers/Pointer.h>
@@ -1897,8 +1896,13 @@ class EmscriptenApplication::TextInputEvent {
         /** @copydoc EmscriptenApplication::InputEvent::setAccepted() */
         void setAccepted(bool accepted = true) { _accepted = accepted; }
 
-        /** @brief Input text in UTF-8 */
-        Containers::ArrayView<const char> text() const { return _text; }
+        /**
+         * @brief Input text
+         *
+         * The returned view is in UTF-8 and is always
+         * @relativeref{Corrade,Containers::StringViewFlag::NullTerminated}.
+         */
+        Containers::StringView text() const { return _text; }
 
         /** @brief Underlying Emscripten event */
         const EmscriptenKeyboardEvent& event() const { return _event; }
@@ -1906,10 +1910,10 @@ class EmscriptenApplication::TextInputEvent {
     private:
         friend EmscriptenApplication;
 
-        explicit TextInputEvent(const EmscriptenKeyboardEvent& event, Containers::ArrayView<const char> text): _event(event), _text{text}, _accepted{false} {}
+        explicit TextInputEvent(const EmscriptenKeyboardEvent& event, Containers::StringView text): _event(event), _text{text}, _accepted{false} {}
 
         const EmscriptenKeyboardEvent& _event;
-        const Containers::ArrayView<const char> _text;
+        const Containers::StringView _text;
         bool _accepted;
 };
 

src/Magnum/Platform/GlfwApplication.cpp

@@ -654,9 +654,10 @@ void GlfwApplication::setupCallbacks() {
 
         if(!(app._flags & Flag::TextInputActive)) return;
 
-        char utf8[4]{};
-        const std::size_t size = Utility::Unicode::utf8(codepoint, utf8);
-        TextInputEvent e{{utf8, size}};
+        /* One extra byte to ensure it gets always null-terminated */
+        char utf8[4 + 1]{};
+        const std::size_t size = Utility::Unicode::utf8(codepoint, Containers::staticArrayView(utf8).prefix<4>());
+        TextInputEvent e{{utf8, size, Containers::StringViewFlag::NullTerminated}};
         app.textInputEvent(e);
     });
 }

src/Magnum/Platform/GlfwApplication.h

@@ -32,7 +32,6 @@
  * @brief Class @ref Magnum::Platform::GlfwApplication, macro @ref MAGNUM_GLFWAPPLICATION_MAIN()
  */
 
-#include <Corrade/Containers/ArrayView.h>
 #include <Corrade/Containers/Optional.h>
 #include <Corrade/Containers/String.h> /** @todo PIMPL Configuration instead? */
 
@@ -2050,15 +2049,20 @@ class GlfwApplication::TextInputEvent {
          */
         void setAccepted(bool accepted = true) { _accepted = accepted; }
 
-        /** @brief Input text in UTF-8 */
-        Containers::ArrayView<const char> text() const { return _text; }
+        /**
+         * @brief Input text
+         *
+         * The returned view is in UTF-8 and is always
+         * @relativeref{Corrade,Containers::StringViewFlag::NullTerminated}.
+         */
+        Containers::StringView text() const { return _text; }
 
     private:
         friend GlfwApplication;
 
-        explicit TextInputEvent(Containers::ArrayView<const char> text): _text{text}, _accepted{false} {}
+        explicit TextInputEvent(Containers::StringView text): _text{text}, _accepted{false} {}
 
-        const Containers::ArrayView<const char> _text;
+        const Containers::StringView _text;
         bool _accepted;
 };
 

src/Magnum/Platform/Sdl2Application.cpp

@@ -27,7 +27,6 @@
 
 #include "Sdl2Application.h"
 
-#include <cstring> /** @todo remove, needed for std::strlen() in TextInputEvent */
 #ifdef CORRADE_TARGET_CLANG_CL
 /* SDL does #pragma pack(push,8) and #pragma pack(pop,8) in different headers
    (begin_code.h and end_code.h) and clang-cl doesn't like that, even though it
@@ -963,12 +962,12 @@ bool Sdl2Application::mainLoopIteration() {
             }
 
             case SDL_TEXTINPUT: {
-                TextInputEvent e{event, {event.text.text, std::strlen(event.text.text)}};
+                TextInputEvent e{event, event.text.text};
                 textInputEvent(e);
             } break;
 
             case SDL_TEXTEDITING: {
-                TextEditingEvent e{event, {event.edit.text, std::strlen(event.text.text)}, event.edit.start, event.edit.length};
+                TextEditingEvent e{event, event.edit.text, event.edit.start, event.edit.length};
                 textEditingEvent(e);
             } break;
 

src/Magnum/Platform/Sdl2Application.h

@@ -31,7 +31,6 @@
  * @brief Class @ref Magnum::Platform::Sdl2Application, macro @ref MAGNUM_SDL2APPLICATION_MAIN()
  */
 
-#include <Corrade/Containers/ArrayView.h>
 #include <Corrade/Containers/EnumSet.h>
 #include <Corrade/Containers/Optional.h>
 #include <Corrade/Containers/String.h> /** @todo PIMPL Configuration instead? */
@@ -2798,8 +2797,13 @@ class Sdl2Application::TextInputEvent {
          */
         void setAccepted(bool accepted = true) { _accepted = accepted; }
 
-        /** @brief Input text in UTF-8 */
-        Containers::ArrayView<const char> text() const { return _text; }
+        /**
+         * @brief Input text
+         *
+         * The returned view is in UTF-8 and is always
+         * @relativeref{Corrade,Containers::StringViewFlag::NullTerminated}.
+         */
+        Containers::StringView text() const { return _text; }
 
         /**
          * @brief Underlying SDL event
@@ -2812,10 +2816,10 @@ class Sdl2Application::TextInputEvent {
     private:
         friend Sdl2Application;
 
-        explicit TextInputEvent(const SDL_Event& event, Containers::ArrayView<const char> text): _event(event), _text{text}, _accepted{false} {}
+        explicit TextInputEvent(const SDL_Event& event, Containers::StringView text): _event(event), _text{text}, _accepted{false} {}
 
         const SDL_Event& _event;
-        const Containers::ArrayView<const char> _text;
+        const Containers::StringView _text;
         bool _accepted;
 };
 
@@ -2851,8 +2855,13 @@ class Sdl2Application::TextEditingEvent {
          */
         void setAccepted(bool accepted = true) { _accepted = accepted; }
 
-        /** @brief Input text in UTF-8 */
-        Containers::ArrayView<const char> text() const { return _text; }
+        /**
+         * @brief Input text
+         *
+         * The returned view is in UTF-8 and is always
+         * @relativeref{Corrade,Containers::StringViewFlag::NullTerminated}.
+         */
+        Containers::StringView text() const { return _text; }
 
         /** @brief Location to begin editing from */
         Int start() const { return _start; }
@@ -2871,10 +2880,10 @@ class Sdl2Application::TextEditingEvent {
     private:
         friend Sdl2Application;
 
-        explicit TextEditingEvent(const SDL_Event& event, Containers::ArrayView<const char> text, Int start, Int length): _event(event), _text{text}, _start{start}, _length{length}, _accepted{false} {}
+        explicit TextEditingEvent(const SDL_Event& event, Containers::StringView text, Int start, Int length): _event(event), _text{text}, _start{start}, _length{length}, _accepted{false} {}
 
         const SDL_Event& _event;
-        const Containers::ArrayView<const char> _text;
+        const Containers::StringView _text;
         const Int _start;
         const Int _length;
         bool _accepted;

src/Magnum/Platform/Test/EmscriptenApplicationTest.cpp

@@ -26,7 +26,6 @@
 */
 
 #include <Corrade/Utility/Arguments.h>
-#include <Corrade/Utility/DebugStl.h>
 
 #include "Magnum/Platform/EmscriptenApplication.h"
 #include "Magnum/GL/Renderer.h"
@@ -140,7 +139,7 @@ struct EmscriptenApplicationTest: Platform::Application {
     }
 
     void textInputEvent(TextInputEvent& event) override {
-        Debug{} << "text input event:" << std::string{event.text(), event.text().size()};
+        Debug{} << "text input event:" << event.text();
 
         event.setAccepted();
     }

src/Magnum/Platform/Test/GlfwApplicationTest.cpp

@@ -26,7 +26,6 @@
 #include <Corrade/Containers/Optional.h>
 #include <Corrade/PluginManager/Manager.h>
 #include <Corrade/Utility/Arguments.h>
-#include <Corrade/Utility/DebugStl.h>
 #include <Corrade/Utility/Resource.h>
 
 #include "Magnum/ImageView.h"
@@ -102,7 +101,7 @@ struct GlfwApplicationTest: Platform::Application {
     }
 
     void textInputEvent(TextInputEvent& event) override {
-        Debug{} << "text input event:" << std::string{event.text(), event.text().size()};
+        Debug{} << "text input event:" << event.text();
     }
 };
 

src/Magnum/Platform/Test/Sdl2ApplicationTest.cpp

@@ -26,7 +26,6 @@
 #include <Corrade/Containers/Optional.h>
 #include <Corrade/PluginManager/Manager.h>
 #include <Corrade/Utility/Arguments.h>
-#include <Corrade/Utility/DebugStl.h>
 #include <Corrade/Utility/Resource.h>
 
 #include "Magnum/ImageView.h"
@@ -142,7 +141,7 @@ struct Sdl2ApplicationTest: Platform::Application {
     }
 
     void textInputEvent(TextInputEvent& event) override {
-        Debug{} << "text input event:" << std::string{event.text(), event.text().size()};
+        Debug{} << "text input event:" << event.text();
     }
 
     /* Should fire on currently not handled events, such as minimize/maximize