Properly implement text editor paragraph-on-cursor selection

src/gui/TextEditor.cpp

@@ -454,20 +454,21 @@ void TextEditor::selectAtCursor(TextEditor::SelectType ty)
 	XOJ_CHECK_TYPE(TextEditor);
 
 	GtkTextMark* mark = gtk_text_buffer_get_insert(this->buffer);
-	GtkTextIter currentPos;
-	gtk_text_buffer_get_iter_at_mark(this->buffer, &currentPos, mark);
-
-	// Only process double click
-	if (!gtk_text_iter_inside_word(&currentPos))
-	{
-		return;
-	}
-
-	GtkTextIter startPos = currentPos;
-	GtkTextIter endPos = currentPos;
+	GtkTextIter startPos;
+	GtkTextIter endPos;
+	gtk_text_buffer_get_selection_bounds(this->buffer, &startPos, &endPos);
+	const auto searchFlag = GTK_TEXT_SEARCH_TEXT_ONLY; // To be used to find double newlines
 
 	switch(ty) {
 	case TextEditor::SelectType::word:
+		// Do nothing if cursor is over whitespace
+		GtkTextIter currentPos;
+		gtk_text_buffer_get_iter_at_mark(this->buffer, &currentPos, mark);
+		if (!gtk_text_iter_inside_word(&currentPos))
+		{
+			return;
+		}
+
 		if (!gtk_text_iter_starts_word(&currentPos))
 		{
 			gtk_text_iter_backward_word_start(&startPos);
@@ -478,13 +479,38 @@ void TextEditor::selectAtCursor(TextEditor::SelectType ty)
 		}
 		break;
 	case TextEditor::SelectType::paragraph:
-		if (!gtk_text_iter_starts_line(&currentPos))
+		// Note that a GTK "paragraph" is a line, so there's no nice one-liner.
+		// We define a paragraph as text separated by double newlines.
+		while (!gtk_text_iter_is_start(&startPos))
 		{
+			// There's no GTK function to go to line start, so do it manually.
+			while (!gtk_text_iter_starts_line(&startPos))
+			{
+				if (!gtk_text_iter_backward_word_start(&startPos))
+				{
+					break;
+				}
+			}
+			// Check for paragraph start
+			GtkTextIter searchPos = startPos;
+			gtk_text_iter_backward_chars(&searchPos, 2);
+			if (gtk_text_iter_backward_search(&startPos, "\n\n", searchFlag, nullptr, nullptr, &searchPos))
+			{
+				break;
+			}
 			gtk_text_iter_backward_line(&startPos);
 		}
-		if (!gtk_text_iter_ends_line(&currentPos))
+		while (!gtk_text_iter_ends_line(&endPos))
 		{
 			gtk_text_iter_forward_to_line_end(&endPos);
+			// Check for paragraph end
+			GtkTextIter searchPos = endPos;
+			gtk_text_iter_forward_chars(&searchPos, 2);
+			if (gtk_text_iter_forward_search(&endPos, "\n\n", searchFlag, nullptr, nullptr, &searchPos))
+			{
+				break;
+			}
+			gtk_text_iter_forward_line(&endPos);
 		}
 		break;
 	case TextEditor::SelectType::all: