Implement column title alignment for `Tree`

doc/classes/Tree.xml

@@ -100,6 +100,13 @@
 				Returns the column's title.
 			</description>
 		</method>
+		<method name="get_column_title_alignment" qualifiers="const">
+			<return type="int" enum="HorizontalAlignment" />
+			<param index="0" name="column" type="int" />
+			<description>
+				Returns the column title alignment.
+			</description>
+		</method>
 		<method name="get_column_title_direction" qualifiers="const">
 			<return type="int" enum="Control.TextDirection" />
 			<param index="0" name="column" type="int" />
@@ -288,6 +295,14 @@
 				Sets the title of a column.
 			</description>
 		</method>
+		<method name="set_column_title_alignment">
+			<return type="void" />
+			<param index="0" name="column" type="int" />
+			<param index="1" name="title_alignment" type="int" enum="HorizontalAlignment" />
+			<description>
+				Sets the column title alignment. Note that [constant @GlobalScope.HORIZONTAL_ALIGNMENT_FILL] is not supported for column titles.
+			</description>
+		</method>
 		<method name="set_column_title_direction">
 			<return type="void" />
 			<param index="0" name="column" type="int" />

scene/gui/tree.cpp

@@ -4045,7 +4045,24 @@ void Tree::_notification(int p_what) {
 					int clip_w = tbrect.size.width - sb->get_minimum_size().width;
 					columns.write[i].text_buf->set_width(clip_w);
 
-					Vector2 text_pos = tbrect.position + Point2i(sb->get_offset().x + (tbrect.size.width - columns[i].text_buf->get_size().x) / 2, (tbrect.size.height - columns[i].text_buf->get_size().y) / 2);
+					Vector2 text_pos = Point2i(tbrect.position.x, tbrect.position.y + (tbrect.size.height - columns[i].text_buf->get_size().y) / 2);
+					switch (columns[i].title_alignment) {
+						case HorizontalAlignment::HORIZONTAL_ALIGNMENT_LEFT: {
+							text_pos.x += cache.rtl ? tbrect.size.width - (sb->get_offset().x + columns[i].text_buf->get_size().x) : sb->get_offset().x;
+							break;
+						}
+
+						case HorizontalAlignment::HORIZONTAL_ALIGNMENT_RIGHT: {
+							text_pos.x += cache.rtl ? sb->get_offset().x : tbrect.size.width - (sb->get_offset().x + columns[i].text_buf->get_size().x);
+							break;
+						}
+
+						default: {
+							text_pos.x += sb->get_offset().x + (tbrect.size.width - columns[i].text_buf->get_size().x) / 2;
+							break;
+						}
+					}
+
 					if (theme_cache.font_outline_size > 0 && theme_cache.font_outline_color.a > 0) {
 						columns[i].text_buf->draw_outline(ci, text_pos, theme_cache.font_outline_size, theme_cache.font_outline_color);
 					}
@@ -4681,6 +4698,27 @@ String Tree::get_column_title(int p_column) const {
 	return columns[p_column].title;
 }
 
+void Tree::set_column_title_alignment(int p_column, HorizontalAlignment p_alignment) {
+	ERR_FAIL_INDEX(p_column, columns.size());
+
+	if (p_alignment == HORIZONTAL_ALIGNMENT_FILL) {
+		WARN_PRINT("HORIZONTAL_ALIGNMENT_FILL is not supported for column titles.");
+	}
+
+	if (columns[p_column].title_alignment == p_alignment) {
+		return;
+	}
+
+	columns.write[p_column].title_alignment = p_alignment;
+	update_column(p_column);
+	queue_redraw();
+}
+
+HorizontalAlignment Tree::get_column_title_alignment(int p_column) const {
+	ERR_FAIL_INDEX_V(p_column, columns.size(), HorizontalAlignment::HORIZONTAL_ALIGNMENT_CENTER);
+	return columns[p_column].title_alignment;
+}
+
 void Tree::set_column_title_direction(int p_column, Control::TextDirection p_text_direction) {
 	ERR_FAIL_INDEX(p_column, columns.size());
 	ERR_FAIL_COND((int)p_text_direction < -1 || (int)p_text_direction > 3);
@@ -5211,6 +5249,9 @@ void Tree::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_column_title", "column", "title"), &Tree::set_column_title);
 	ClassDB::bind_method(D_METHOD("get_column_title", "column"), &Tree::get_column_title);
 
+	ClassDB::bind_method(D_METHOD("set_column_title_alignment", "column", "title_alignment"), &Tree::set_column_title_alignment);
+	ClassDB::bind_method(D_METHOD("get_column_title_alignment", "column"), &Tree::get_column_title_alignment);
+
 	ClassDB::bind_method(D_METHOD("set_column_title_direction", "column", "direction"), &Tree::set_column_title_direction);
 	ClassDB::bind_method(D_METHOD("get_column_title_direction", "column"), &Tree::get_column_title_direction);
 

scene/gui/tree.h

@@ -435,6 +435,7 @@ private:
 		bool expand = true;
 		bool clip_content = false;
 		String title;
+		HorizontalAlignment title_alignment = HORIZONTAL_ALIGNMENT_CENTER;
 		Ref<TextLine> text_buf;
 		String language;
 		Control::TextDirection text_direction = Control::TEXT_DIRECTION_INHERITED;
@@ -680,6 +681,9 @@ public:
 	void set_column_title(int p_column, const String &p_title);
 	String get_column_title(int p_column) const;
 
+	void set_column_title_alignment(int p_column, HorizontalAlignment p_alignment);
+	HorizontalAlignment get_column_title_alignment(int p_column) const;
+
 	void set_column_title_direction(int p_column, Control::TextDirection p_text_direction);
 	Control::TextDirection get_column_title_direction(int p_column) const;