HaikuDepot: Added work-in-progress TextEditor class

The intention here is to be able to set it on a TextDocumentView to add
editing capabilities.

src/apps/haiku-depot/Jamfile

@@ -26,6 +26,8 @@ local textDocumentSources =
 	TextDocument.cpp
 	TextDocumentLayout.cpp
 	TextDocumentView.cpp
+	TextEditor.cpp
+	TextSelection.cpp
 	TextSpan.cpp
 	TextView.cpp
 ;

src/apps/haiku-depot/textview/TextEditor.cpp

@@ -0,0 +1,345 @@
+/*
+ * Copyright 2014, Stephan Aßmus <[email protected]>.
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+
+#include "TextEditor.h"
+
+#include <algorithm>
+
+
+TextEditor::TextEditor()
+	:
+	fDocument(),
+	fLayout(),
+	fSelection(),
+	fCaretAnchorX(0.0f),
+	fStyleAtCaret()
+{
+}
+
+
+TextEditor::TextEditor(const TextEditor& other)
+	:
+	fDocument(other.fDocument),
+	fLayout(other.fLayout),
+	fSelection(other.fSelection),
+	fCaretAnchorX(other.fCaretAnchorX),
+	fStyleAtCaret(other.fStyleAtCaret)
+{
+}
+
+
+TextEditor&
+TextEditor::operator=(const TextEditor& other)
+{
+	if (this == &other)
+		return *this;
+
+	fDocument = other.fDocument;
+	fLayout = other.fLayout;
+	fSelection = other.fSelection;
+	fCaretAnchorX = other.fCaretAnchorX;
+	fStyleAtCaret = other.fStyleAtCaret;
+	return *this;
+}
+
+
+bool
+TextEditor::operator==(const TextEditor& other) const
+{
+	if (this == &other)
+		return true;
+
+	return fDocument == other.fDocument
+		&& fLayout == other.fLayout
+		&& fSelection == other.fSelection
+		&& fCaretAnchorX == other.fCaretAnchorX
+		&& fStyleAtCaret == other.fStyleAtCaret;
+}
+
+
+bool
+TextEditor::operator!=(const TextEditor& other) const
+{
+	return !(*this == other);
+}
+
+
+// #pragma mark -
+
+
+void
+TextEditor::SetDocument(const TextDocumentRef& ref)
+{
+	fDocument = ref;
+	SetSelection(TextSelection());
+}
+
+
+void
+TextEditor::SetLayout(const TextDocumentLayoutRef& ref)
+{
+	fLayout = ref;
+	SetSelection(TextSelection());
+}
+
+
+void
+TextEditor::SetSelection(TextSelection selection)
+{
+	_SetSelection(selection.Caret(), selection.Anchor(), true, true);
+}
+
+
+void
+TextEditor::SetCharacterStyle(::CharacterStyle style)
+{
+	if (fStyleAtCaret == style)
+		return;
+
+	fStyleAtCaret = style;
+
+	if (fSelection.Caret() != fSelection.Anchor()) {
+		// TODO: Apply style to selection range
+	}
+}
+
+
+void
+TextEditor::KeyDown(KeyEvent event)
+{
+	if (fDocument.Get() == NULL)
+		return;
+
+	bool select = (event.modifiers & B_SHIFT_KEY) != 0;
+
+	switch (event.key) {
+		case B_UP_ARROW:
+			_LineUp(select);
+			break;
+
+		case B_DOWN_ARROW:
+			_LineDown(select);
+			break;
+
+		case B_LEFT_ARROW:
+			if (_HasSelection() && !select) {
+				_SetCaretOffset(
+					std::min(fSelection.Caret(), fSelection.Anchor()),
+					true, false, true
+				);
+			} else
+				_SetCaretOffset(fSelection.Caret() - 1, true, select, true);
+			break;
+
+		case B_RIGHT_ARROW:
+			if (_HasSelection() && !select) {
+				_SetCaretOffset(
+					std::max(fSelection.Caret(), fSelection.Anchor()),
+					true, false, true
+				);
+			} else
+				_SetCaretOffset(fSelection.Caret() + 1, true, select, true);
+			break;
+
+		case B_HOME:
+			_LineStart(select);
+			break;
+
+		case B_END:
+			_LineEnd(select);
+			break;
+
+		case B_ENTER:
+			Insert(fSelection.Caret(), "\n");
+			break;
+
+		case B_TAB:
+			// TODO: Tab support in TextLayout
+			Insert(fSelection.Caret(), " ");
+			break;
+
+		case B_ESCAPE:
+			break;
+
+		case B_BACKSPACE:
+			if (_HasSelection()) {
+				Remove(_SelectionStart(), _SelectionLength());
+			} else {
+				if (fSelection.Caret() > 0)
+					Remove(fSelection.Caret() - 1, 1);
+			}
+			break;
+
+		case B_DELETE:
+			if (_HasSelection()) {
+				Remove(_SelectionStart(), _SelectionLength());
+			} else {
+				if (fSelection.Caret() < fDocument->Length())
+					Remove(fSelection.Caret(), 1);
+			}
+			break;
+
+		case B_INSERT:
+			// TODO: Toggle insert mode (or maybe just don't support it)
+			break;
+
+		case B_PAGE_UP:
+		case B_PAGE_DOWN:
+		case B_SUBSTITUTE:
+		case B_FUNCTION_KEY:
+		case B_KATAKANA_HIRAGANA:
+		case B_HANKAKU_ZENKAKU:
+			break;
+
+		default:
+			if (event.bytes != NULL && event.length > 0) {
+				// Handle null-termintating the string
+				BString text(event.bytes, event.length);
+				Insert(fSelection.Caret(), text);
+			}
+			break;
+	}
+}
+
+
+void
+TextEditor::Insert(int32 offset, const BString& string)
+{
+	// TODO: ...
+}
+
+
+void
+TextEditor::Remove(int32 offset, int32 length)
+{
+	// TODO: ...
+}
+
+
+// #pragma mark - private
+
+
+// _SetCaretOffset
+void
+TextEditor::_SetCaretOffset(int32 offset, bool updateAnchor,
+	bool lockSelectionAnchor, bool updateSelectionStyle)
+{
+	if (fDocument.Get() == NULL)
+		return;
+
+	if (offset < 0)
+		offset = 0;
+	int32 textLength = fDocument->Length();
+	if (offset > textLength)
+		offset = textLength;
+
+	int32 caret = offset;
+	int32 anchor = lockSelectionAnchor ? fSelection.Anchor() : offset;
+	_SetSelection(caret, anchor, updateAnchor, updateSelectionStyle);
+}
+
+
+// _SetSelection
+void
+TextEditor::_SetSelection(int32 caret, int32 anchor, bool updateAnchor,
+	bool updateSelectionStyle)
+{
+	if (fLayout.Get() == NULL)
+		return;
+	
+	if (caret == fSelection.Caret() && caret == fSelection.Anchor())
+		return;
+
+	fSelection.SetAnchor(anchor);
+	fSelection.SetCaret(caret);
+
+	if (updateAnchor) {
+		float x1;
+		float y1;
+		float x2;
+		float y2;
+
+		fLayout->GetTextBounds(caret, x1, y1, x2, y2);
+		fCaretAnchorX = x1;
+	}
+
+	if (updateSelectionStyle)
+		_UpdateStyleAtCaret();
+}
+
+
+void
+TextEditor::_UpdateStyleAtCaret()
+{
+	if (fDocument.Get() == NULL)
+		return;
+
+	int32 offset = fSelection.Caret() - 1;
+	if (offset < 0)
+		offset = 0;
+	SetCharacterStyle(fDocument->CharacterStyleAt(offset));
+}
+
+
+// #pragma mark -
+
+
+void
+TextEditor::_LineUp(bool select)
+{
+	// TODO
+}
+
+
+void
+TextEditor::_LineDown(bool select)
+{
+	// TODO
+}
+
+
+void
+TextEditor::_LineStart(bool select)
+{
+	// TODO
+}
+
+
+void
+TextEditor::_LineEnd(bool select)
+{
+	// TODO
+}
+
+
+// #pragma mark -
+
+
+bool
+TextEditor::_HasSelection() const
+{
+	return _SelectionLength() > 0;
+}
+
+
+int32
+TextEditor::_SelectionStart() const
+{
+	return std::min(fSelection.Caret(), fSelection.Anchor());
+}
+
+
+int32
+TextEditor::_SelectionEnd() const
+{
+	return std::max(fSelection.Caret(), fSelection.Anchor());
+}
+
+
+int32
+TextEditor::_SelectionLength() const
+{
+	return _SelectionEnd() - _SelectionStart();
+}

src/apps/haiku-depot/textview/TextEditor.h

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2014, Stephan Aßmus <[email protected]>.
+ * All rights reserved. Distributed under the terms of the MIT License.
+ */
+#ifndef TEXT_EDITOR_H
+#define TEXT_EDITOR_H
+
+
+#include "CharacterStyle.h"
+#include "TextDocument.h"
+#include "TextDocumentLayout.h"
+#include "TextSelection.h"
+
+
+class KeyEvent {
+public:
+			const char*			bytes;
+			int32				length;
+			int32				key;
+			int32				modifiers;
+};
+
+
+class TextEditor {
+public:
+								TextEditor();
+								TextEditor(const TextEditor& other);
+
+			TextEditor&			operator=(const TextEditor& other);
+			bool				operator==(const TextEditor& other) const;
+			bool				operator!=(const TextEditor& other) const;
+
+			void				SetDocument(const TextDocumentRef& ref);
+			TextDocumentRef		Document() const
+									{ return fDocument; }
+
+			void				SetLayout(
+									const TextDocumentLayoutRef& ref);
+			TextDocumentLayoutRef Layout() const
+									{ return fLayout; }
+
+			void				SetSelection(TextSelection selection);
+	inline	TextSelection		Selection() const
+									{ return fSelection; }
+
+			void				SetCharacterStyle(::CharacterStyle style);
+			::CharacterStyle	CharacterStyle() const
+									{ return fStyleAtCaret; }
+
+			void				KeyDown(KeyEvent event);
+
+			void				Insert(int32 offset, const BString& string);
+			void				Remove(int32 offset, int32 length);
+
+private:
+			void				_SetCaretOffset(int32 offset,
+									bool updateAnchor,
+									bool lockSelectionAnchor,
+									bool updateSelectionStyle);
+			void				_SetSelection(int32 caret, int32 anchor,
+									bool updateAnchor,
+									bool updateSelectionStyle);
+
+			void				_UpdateStyleAtCaret();
+
+			void				_LineUp(bool select);
+			void				_LineDown(bool select);
+			void				_LineStart(bool select);
+			void				_LineEnd(bool select);
+
+			bool				_HasSelection() const;
+			int32				_SelectionStart() const;
+			int32				_SelectionEnd() const;
+			int32				_SelectionLength() const;
+
+private:
+			TextDocumentRef		fDocument;
+			TextDocumentLayoutRef fLayout;
+			TextSelection		fSelection;
+			float				fCaretAnchorX;
+			::CharacterStyle	fStyleAtCaret;
+};
+
+
+#endif // TEXT_EDITOR_H