Prototype item count cache in TreeItem eclipse-platform#822

Add cache invalidation only to obvious places for now.
basilevs · Nov 11, 2023 · 999ba74 · 999ba74
1 parent a362620
commit 999ba74
Showing 1 changed file with 21 additions and 3 deletions.
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TreeItem.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/TreeItem.java
@@ -45,6 +45,7 @@ public class TreeItem extends Item {
 	Font[] cellFont;
 	String [] strings;
 	boolean cached, grayed, isExpanded, updated, settingData;
+	int itemCountCache = -1;
 	static final int EXPANDER_EXTRA_PADDING = 4;
 
 /**
@@ -166,6 +167,7 @@ public TreeItem (TreeItem parentItem, int style, int index) {
 	this.parent = parent;
 	if (create) {
 		parent.createItem (this, parentIter, index);
+		resetParentCache();
 	} else {
 		handle = OS.g_malloc (GTK.GtkTreeIter_sizeof ());
 		GTK.gtk_tree_model_iter_nth_child (parent.modelHandle, handle, parentIter, index);
@@ -768,7 +770,7 @@ Rectangle getImageBoundsInPixels (int index) {
 public int getItemCount () {
 	checkWidget();
 	if (!parent.checkData (this)) error (SWT.ERROR_WIDGET_DISPOSED);
-	return GTK.gtk_tree_model_iter_n_children (parent.modelHandle, handle);
+	return getItemCountImpl();
 }
 
 /**
@@ -791,8 +793,7 @@ public int getItemCount () {
 public TreeItem getItem (int index) {
 	checkWidget();
 	if (index < 0) error (SWT.ERROR_INVALID_RANGE);
-	if (!parent.checkData (this)) error (SWT.ERROR_WIDGET_DISPOSED);
-	int itemCount = GTK.gtk_tree_model_iter_n_children (parent.modelHandle, handle);
+	int itemCount = getItemCountImpl();
 	if (index >= itemCount)  error (SWT.ERROR_INVALID_RANGE);
 	return  parent._getItem (handle, index);
 }
@@ -1099,6 +1100,7 @@ public void dispose () {
  */
 public void removeAll () {
 	checkWidget ();
+	itemCountCache = 0;
 	long modelHandle = parent.modelHandle;
 	int length = GTK.gtk_tree_model_iter_n_children (modelHandle, handle);
 	if (length == 0) return;
@@ -1629,6 +1631,7 @@ public void setImage (Image [] images) {
 public void setItemCount (int count) {
 	checkWidget ();
 	count = Math.max (0, count);
+	itemCountCache = count;
 	parent.setItemCount (handle, count);
 }
 
@@ -1708,4 +1711,19 @@ public void setText (String [] strings) {
 		if (string != null) setText (i, string);
 	}
 }
+
+private void resetParentCache() {
+	TreeItem parentItem = getParentItem();
+	if (parentItem != null) {
+		parentItem.itemCountCache = -1;
+	}
+}
+
+private int getItemCountImpl() {
+	if (itemCountCache < 0) {
+		itemCountCache = GTK.gtk_tree_model_iter_n_children (parent.modelHandle, handle); 
+	}
+	return itemCountCache;
+}
+
 }