Text stuff: Support extracting sub-paragraphs and documents

* Also some WIP towards integrating TextListener.
 * Everything untested.
 * Fixed a bug where copying to the clipboard had an extra line-break
   after each paragraph since the recent changes that made sure each
   paragraph ends in a line-break.

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

@@ -261,12 +261,36 @@ Paragraph::IsEmpty() const
 
 
 BString
-Paragraph::GetText(int32 start, int32 length) const
+Paragraph::Text() const
+{
+	BString result;
+
+	int32 count = fTextSpans.CountItems();
+	for (int32 i = 0; i < count; i++)
+		result << fTextSpans.ItemAtFast(i).Text();
+
+	return result;
+}
+
+
+BString
+Paragraph::Text(int32 start, int32 length) const
+{
+	Paragraph subParagraph = SubParagraph(start, length);
+	return subParagraph.Text();
+}
+
+
+Paragraph
+Paragraph::SubParagraph(int32 start, int32 length) const
 {
 	if (start < 0)
 		start = 0;
 	
-	BString text;
+	if (start == 0 && length == Length())
+		return *this;
+	
+	Paragraph result(fStyle);
 	
 	int32 count = fTextSpans.CountItems();
 	for (int32 i = 0; i < count; i++) {
@@ -284,13 +308,10 @@ Paragraph::GetText(int32 start, int32 length) const
 		spanLength -= start;
 		int32 copyLength = std::min(spanLength, length);
 
-		if (start == 0 && length == spanLength) {
-			text << span.Text();
-		} else {
-			BString subString;
-			span.Text().CopyCharsInto(subString, start, copyLength);
-			text << subString;
-		}
+		if (start == 0 && length == spanLength)
+			result.Append(span);
+		else
+			result.Append(span.SubSpan(start, copyLength));
 		
 		length -= copyLength;
 		if (length == 0)
@@ -300,7 +321,7 @@ Paragraph::GetText(int32 start, int32 length) const
 		start = 0;
 	}
 
-	return text;
+	return result;
 }
 
 

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

@@ -39,7 +39,9 @@ public:
 			int32				Length() const;
 			bool				IsEmpty() const;
 
-			BString				GetText(int32 start, int32 length) const;
+			BString				Text() const;
+			BString				Text(int32 start, int32 length) const;
+			Paragraph			SubParagraph(int32 start, int32 length) const;
 
 			void				PrintToStream() const;
 

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

@@ -394,7 +394,14 @@ TextDocument::Length() const
 
 
 BString
-TextDocument::GetText(int32 start, int32 length) const
+TextDocument::Text() const
+{
+	return Text(0, Length());
+}
+
+
+BString
+TextDocument::Text(int32 start, int32 length) const
 {
 	if (start < 0)
 		start = 0;
@@ -417,13 +424,11 @@ TextDocument::GetText(int32 start, int32 length) const
 		paragraphLength -= start;
 		int32 copyLength = std::min(paragraphLength, length);
 		
-		text << paragraph.GetText(start, copyLength);
+		text << paragraph.Text(start, copyLength);
 		
 		length -= copyLength;
 		if (length == 0)
 			break;
-		else if (i < count - 1)
-			text << '\n';
 
 		// Next paragraph is copied from its beginning
 		start = 0;
@@ -433,6 +438,48 @@ TextDocument::GetText(int32 start, int32 length) const
 }
 
 
+TextDocumentRef
+TextDocument::SubDocument(int32 start, int32 length) const
+{
+	TextDocumentRef result(new(std::nothrow) TextDocument(
+		fDefaultCharacterStyle, fEmptyLastParagraph.Style()), true);
+	
+	if (result.Get() == NULL)
+		return result;
+	
+	if (start < 0)
+		start = 0;
+
+	int32 count = fParagraphs.CountItems();
+	for (int32 i = 0; i < count; i++) {
+		const Paragraph& paragraph = fParagraphs.ItemAtFast(i);
+		int32 paragraphLength = paragraph.Length();
+		if (paragraphLength == 0)
+			continue;
+		if (start > paragraphLength) {
+			// Skip paragraph if its before start
+			start -= paragraphLength;
+			continue;
+		}
+
+		// Remaining paragraph length after start
+		paragraphLength -= start;
+		int32 copyLength = std::min(paragraphLength, length);
+		
+		result->Append(paragraph.SubParagraph(start, copyLength));
+
+		length -= copyLength;
+		if (length == 0)
+			break;
+
+		// Next paragraph is copied from its beginning
+		start = 0;
+	}
+
+	return result;
+}
+
+
 // #pragma mark -
 
 
@@ -450,3 +497,55 @@ TextDocument::PrintToStream() const
 	}
 	printf("</document>\n");
 }
+
+
+// #pragma mark -
+
+
+bool
+TextDocument::AddListener(const TextListenerRef& listener)
+{
+	return fTextListeners.Add(listener);
+}
+
+
+bool
+TextDocument::RemoveListener(const TextListenerRef& listener)
+{
+	return fTextListeners.Remove(listener);
+}
+
+
+void
+TextDocument::_NotifyTextChanging(TextChangingEvent& event) const
+{
+	// Copy listener list to have a stable list in case listeners
+	// are added/removed from within the notification hook.
+	TextListenerList listeners(fTextListeners);
+	int32 count = listeners.CountItems();
+	for (int32 i = 0; i < count; i++) {
+		const TextListenerRef& listener = listeners.ItemAtFast(i);
+		if (listener.Get() == NULL)
+			continue;
+		listener->TextChanging(event);
+		if (event.IsCanceled())
+			break;
+	}
+}
+
+
+void
+TextDocument::_NotifyTextChanged(const TextChangedEvent& event) const
+{
+	// Copy listener list to have a stable list in case listeners
+	// are added/removed from within the notification hook.
+	TextListenerList listeners(fTextListeners);
+	int32 count = listeners.CountItems();
+	for (int32 i = 0; i < count; i++) {
+		const TextListenerRef& listener = listeners.ItemAtFast(i);
+		if (listener.Get() == NULL)
+			continue;
+		listener->TextChanged(event);
+	}
+}
+

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

@@ -10,9 +10,14 @@
 #include "CharacterStyle.h"
 #include "List.h"
 #include "Paragraph.h"
+#include "TextListener.h"
 
 
-typedef List<Paragraph, false>	ParagraphList;
+typedef List<Paragraph, false>			ParagraphList;
+typedef List<TextListenerRef, false>	TextListenerList;
+
+class TextDocument;
+typedef BReference<TextDocument> TextDocumentRef;
 
 
 class TextDocument : public BReferenceable {
@@ -68,18 +73,30 @@ public:
 			// Query information
 			int32				Length() const;
 
-			BString				GetText(int32 textOffset, int32 length) const;
+			BString				Text() const;
+			BString				Text(int32 textOffset, int32 length) const;
+			TextDocumentRef		SubDocument(int32 textOffset,
+									int32 length) const;
 
 			void				PrintToStream() const;
 
+			// Listener support
+			bool				AddListener(const TextListenerRef& listener);
+			bool				RemoveListener(const TextListenerRef& listener);
+
+private:
+			void				_NotifyTextChanging(
+									TextChangingEvent& event) const;
+			void				_NotifyTextChanged(
+									const TextChangedEvent& event) const;
+
 private:
 			ParagraphList		fParagraphs;
 			Paragraph			fEmptyLastParagraph;
 			CharacterStyle		fDefaultCharacterStyle;
+
+			TextListenerList	fTextListeners;
 };
 
 
-typedef BReference<TextDocument> TextDocumentRef;
-
-
 #endif // TEXT_DOCUMENT_H

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

@@ -370,7 +370,7 @@ TextDocumentView::Copy(BClipboard* clipboard)
 		int32 end;
 		GetSelection(start, end);
 		
-		BString text = fTextDocument->GetText(start, end - start);
+		BString text = fTextDocument->Text(start, end - start);
 		clip->AddData("text/plain", B_MIME_TYPE, text.String(),
 			text.Length());