Sdk/Canvas: Implement tab/shift-tab to switch to next/previous widget

ChangeLog.md

@@ -44,6 +44,8 @@ Nazara Development Kit:
 - Add Entity::Disable method, which is a shortcut to Enable(false)
 - Add BaseWidget::HasFocus
 - Fix TextAreaWidget cursor sometimes showing up in readonly mode
+- ⚠️ BaseWidget::OnKeyPressed now returns a boolean to indicate if it should block default action (such as tab to switch to the previous/next widget)
+- Pressing tab/shift-tab will now move to the next/previous widget able to be focused on
 
 # 0.4:
 

SDK/include/NDK/BaseWidget.hpp

@@ -88,9 +88,10 @@ namespace Ndk
 			virtual void Layout();
 			void InvalidateNode() override;
 
+			virtual bool IsFocusable() const;
 			virtual void OnFocusLost();
 			virtual void OnFocusReceived();
-			virtual void OnKeyPressed(const Nz::WindowEvent::KeyEvent& key);
+			virtual bool OnKeyPressed(const Nz::WindowEvent::KeyEvent& key);
 			virtual void OnKeyReleased(const Nz::WindowEvent::KeyEvent& key);
 			virtual void OnMouseEnter();
 			virtual void OnMouseMoved(int x, int y, int deltaX, int deltaY);

SDK/include/NDK/Widgets/TextAreaWidget.hpp

@@ -76,7 +76,7 @@ namespace Ndk
 			bool IsFocusable() const override;
 			void OnFocusLost() override;
 			void OnFocusReceived() override;
-			void OnKeyPressed(const Nz::WindowEvent::KeyEvent& key) override;
+			bool OnKeyPressed(const Nz::WindowEvent::KeyEvent& key) override;
 			void OnKeyReleased(const Nz::WindowEvent::KeyEvent& key) override;
 			void OnMouseButtonPress(int /*x*/, int /*y*/, Nz::Mouse::Button button) override;
 			void OnTextEntered(char32_t character, bool repeated) override;

SDK/src/NDK/BaseWidget.cpp

@@ -189,6 +189,11 @@ namespace Ndk
 			m_canvas->NotifyWidgetBoxUpdate(m_canvasIndex);
 	}
 
+	bool BaseWidget::IsFocusable() const
+	{
+		return false;
+	}
+
 	void BaseWidget::OnFocusLost()
 	{
 	}
@@ -197,8 +202,9 @@ namespace Ndk
 	{
 	}
 
-	void BaseWidget::OnKeyPressed(const Nz::WindowEvent::KeyEvent& /*key*/)
+	bool BaseWidget::OnKeyPressed(const Nz::WindowEvent::KeyEvent& key)
 	{
+		return false;
 	}
 
 	void BaseWidget::OnKeyReleased(const Nz::WindowEvent::KeyEvent& /*key*/)

SDK/src/NDK/Canvas.cpp

@@ -144,7 +144,57 @@ namespace Ndk
 	void Canvas::OnEventKeyPressed(const Nz::EventHandler* /*eventHandler*/, const Nz::WindowEvent::KeyEvent& event)
 	{
 		if (m_keyboardOwner != InvalidCanvasIndex)
-			m_widgetEntries[m_keyboardOwner].widget->OnKeyPressed(event);
+		{
+			if (m_widgetEntries[m_keyboardOwner].widget->OnKeyPressed(event))
+				return;
+
+			if (event.code == Nz::Keyboard::Tab)
+			{
+				if (!event.shift)
+				{
+					// Forward
+					for (std::size_t i = m_keyboardOwner + 1; i < m_widgetEntries.size(); ++i)
+					{
+						if (m_widgetEntries[i].widget->IsFocusable())
+						{
+							SetKeyboardOwner(i);
+							return;
+						}
+					}
+
+					for (std::size_t i = 0; i < m_keyboardOwner; ++i)
+					{
+						if (m_widgetEntries[i].widget->IsFocusable())
+						{
+							SetKeyboardOwner(i);
+							return;
+						}
+					}
+				}
+				else
+				{
+					// Backward
+					for (decltype(m_widgetEntries)::reverse_iterator rit{ m_widgetEntries.begin() + m_keyboardOwner }; rit != m_widgetEntries.rend(); ++rit)
+					{
+						if (rit->widget->IsFocusable())
+						{
+							SetKeyboardOwner(std::distance(m_widgetEntries.begin(), rit.base()) - 1);
+							return;
+						}
+					}
+
+					decltype(m_widgetEntries)::reverse_iterator rend { m_widgetEntries.begin() + m_keyboardOwner };
+					for (auto rit = m_widgetEntries.rbegin(); rit != rend; ++rit)
+					{
+						if (rit->widget->IsFocusable())
+						{
+							SetKeyboardOwner(std::distance(m_widgetEntries.begin(), rit.base()) - 1);
+							return;
+						}
+					}
+				}
+			}
+		}
 	}
 
 	void Canvas::OnEventKeyReleased(const Nz::EventHandler* /*eventHandler*/, const Nz::WindowEvent::KeyEvent& event)

SDK/src/NDK/Widgets/TextAreaWidget.cpp

@@ -134,9 +134,14 @@ namespace Ndk
 		RefreshCursor();
 	}
 
+	bool TextAreaWidget::IsFocusable() const
+	{
+		return !m_readOnly;
+	}
+
 	void TextAreaWidget::OnFocusLost()
 	{
-		m_cursorEntity->Enable(false);
+		m_cursorEntity->Disable();
 	}
 
 	void TextAreaWidget::OnFocusReceived()
@@ -145,7 +150,7 @@ namespace Ndk
 			m_cursorEntity->Enable(true);
 	}
 
-	void TextAreaWidget::OnKeyPressed(const Nz::WindowEvent::KeyEvent& key)
+	bool TextAreaWidget::OnKeyPressed(const Nz::WindowEvent::KeyEvent& key)
 	{
 		switch (key.code)
 		{
@@ -155,7 +160,7 @@ namespace Ndk
 
 				std::size_t textLength = m_text.GetLength();
 				if (cursorGlyph > textLength)
-					break;
+					return true;
 
 				Nz::String newText;
 				if (cursorGlyph > 0)
@@ -165,7 +170,7 @@ namespace Ndk
 					newText.Append(m_text.SubString(m_text.GetCharacterPosition(cursorGlyph + 1)));
 
 				SetText(newText);
-				break;
+				return true;
 			}
 
 			case Nz::Keyboard::Down:
@@ -174,10 +179,10 @@ namespace Ndk
 				OnTextAreaKeyDown(this, &ignoreDefaultAction);
 
 				if (ignoreDefaultAction)
-					break;
+					return true;
 
 				MoveCursor({0, 1});
-				break;
+				return true;
 			}
 
 			case Nz::Keyboard::Left:
@@ -186,10 +191,10 @@ namespace Ndk
 				OnTextAreaKeyLeft(this, &ignoreDefaultAction);
 
 				if (ignoreDefaultAction)
-					break;
+					return true;
 
 				MoveCursor(-1);
-				break;
+				return true;
 			}
 
 			case Nz::Keyboard::Right:
@@ -198,10 +203,10 @@ namespace Ndk
 				OnTextAreaKeyRight(this, &ignoreDefaultAction);
 
 				if (ignoreDefaultAction)
-					break;
+					return true;
 
 				MoveCursor(1);
-				break;
+				return true;
 			}
 
 			case Nz::Keyboard::Up:
@@ -210,14 +215,14 @@ namespace Ndk
 				OnTextAreaKeyUp(this, &ignoreDefaultAction);
 
 				if (ignoreDefaultAction)
-					break;
+					return true;
 
 				MoveCursor({0, -1});
-				break;
+				return true;
 			}
 
 			default:
-				break;
+				return false;
 		}
 	}