[Gtk3] Resize Tree columns on setImage

Fixes #1739

Author: akurtakov

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os.c

@@ -8536,6 +8536,16 @@ JNIEXPORT void JNICALL GTK_NATIVE(gtk_1tree_1view_1column_1set_1widget)
 }
 #endif
 
+#ifndef NO_gtk_1tree_1view_1columns_1autosize
+JNIEXPORT void JNICALL GTK_NATIVE(gtk_1tree_1view_1columns_1autosize)
+	(JNIEnv *env, jclass that, jlong arg0)
+{
+	GTK_NATIVE_ENTER(env, that, gtk_1tree_1view_1columns_1autosize_FUNC);
+	gtk_tree_view_columns_autosize((GtkTreeView *)arg0);
+	GTK_NATIVE_EXIT(env, that, gtk_1tree_1view_1columns_1autosize_FUNC);
+}
+#endif
+
 #ifndef NO_gtk_1tree_1view_1convert_1bin_1window_1to_1tree_1coords
 JNIEXPORT void JNICALL GTK_NATIVE(gtk_1tree_1view_1convert_1bin_1window_1to_1tree_1coords)
 	(JNIEnv *env, jclass that, jlong arg0, jint arg1, jint arg2, jintArray arg3, jintArray arg4)

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/library/os_stats.h

@@ -685,6 +685,7 @@ typedef enum {
 	gtk_1tree_1view_1column_1set_1sort_1order_FUNC,
 	gtk_1tree_1view_1column_1set_1visible_FUNC,
 	gtk_1tree_1view_1column_1set_1widget_FUNC,
+	gtk_1tree_1view_1columns_1autosize_FUNC,
 	gtk_1tree_1view_1convert_1bin_1window_1to_1tree_1coords_FUNC,
 	gtk_1tree_1view_1convert_1bin_1window_1to_1widget_1coords_FUNC,
 	gtk_1tree_1view_1create_1row_1drag_1icon_FUNC,

bundles/org.eclipse.swt/Eclipse SWT PI/gtk/org/eclipse/swt/internal/gtk/GTK.java

@@ -2130,6 +2130,8 @@ public class GTK extends OS {
 	public static final native void gtk_tree_view_move_column_after(long tree_view, long column, long base_column);
 	/** @param model cast=(GtkTreeModel *) */
 	public static final native long gtk_tree_view_new_with_model(long model);
+	/** @param tree_view cast=(GtkTreeView *) */
+	public static final native void gtk_tree_view_columns_autosize(long tree_view);
 	/**
 	 * @param tree_view cast=(GtkTreeView *)
 	 * @param column cast=(GtkTreeViewColumn *)

bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TreeItem.java

@@ -1522,13 +1522,11 @@ public void setImage(int index, Image image) {
 				 * bug 480261.
 				 *
 				 * Toggle the fixed-height-mode GObject property
-				 * off and back on. This resets GTK's cached row height
-				 * (fixed_height = -1) and schedules an async widget resize,
-				 * so GTK will re-measure on the next layout pass and pick
-				 * up the updated renderer size.
+				 * off, autoresize columns and back on.
 				 */
 				if ((parent.style & SWT.VIRTUAL) != 0) {
 					OS.g_object_set(parent.handle, OS.fixed_height_mode, false, 0);
+					GTK.gtk_tree_view_columns_autosize(parent.handle);
 					OS.g_object_set(parent.handle, OS.fixed_height_mode, true, 0);
 				}
 			}