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-rw-r--r--bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Combo.java111
1 files changed, 88 insertions, 23 deletions
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Combo.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Combo.java
index d9f95a3ad8..4718fa2440 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Combo.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/Combo.java
@@ -81,6 +81,8 @@ public class Combo extends Composite {
LIMIT = 0xFFFF;
}
+ private boolean delayedEnableWrap = false; // Bug 489640. Gtk3.
+
/**
* Constructs a new instance of this class given its parent
* and a style value describing its behavior and appearance.
@@ -176,17 +178,80 @@ public void add (String string, int index) {
newItems [index] = string;
System.arraycopy (items, index, newItems, index + 1, items.length - index);
items = newItems;
- byte [] buffer = Converter.wcsToMbcs (string, true);
- if (GTK.GTK3) {
- if (handle != 0) GTK.gtk_combo_box_text_insert (handle, index, null, buffer);
- } else {
- if (handle != 0) GTK.gtk_combo_box_text_insert_text (handle, index, buffer);
- }
+ gtk_combo_box_insert(string, index);
if ((style & SWT.RIGHT_TO_LEFT) != 0 && popupHandle != 0) {
GTK.gtk_container_forall (popupHandle, display.setDirectionProc, GTK.GTK_TEXT_DIR_RTL);
}
}
+private void gtk_combo_box_insert(String string, int index) {
+ byte [] buffer = Converter.wcsToMbcs (string, true);
+ if (handle != 0) {
+ if (GTK.GTK3) {
+ gtk_combo_box_toggle_wrap(false);
+ GTK.gtk_combo_box_text_insert (handle, index, null, buffer);
+ gtk_combo_box_toggle_wrap(true);
+ } else {
+ GTK.gtk_combo_box_text_insert_text (handle, index, buffer);
+ }
+ }
+}
+
+/**
+ * <p>Bug 489640, 438992. Drop-down appearance.</p>
+ *
+ * <p>In Gtk3, there is a lot of white space at the top of the combo drop-down.
+ * It's meant to put the first item near the cursor (See screen shots in bug 438992), but makes eclipse look buggy.</p>
+ *
+ * <p>Solution (438992): gtk_combo_box_get_wrap_width(1) fixes this problem, but introduces a performance regression.
+ * When multiple items are added in a loop, then if 'wrap' is enabled then after every insertion, gtk
+ * traverses the entire list and greedily re-computes the drop-down list size.
+ * This causes O(n^2) performance regression in that the longer the list, the longer the size computation takes.
+ * E.g Adding 1000 items takes almost 30 seconds.</p>
+ *
+ * <p>Solution ^2 (489640): We enabled wrap in a delayed/lazy way, only when display event loop is ran.
+ * This way the insertions occur at O(n) speed and we get the benefit of a neat drop-down list when the user launches the application.
+ * Run-time insertions and combo.add(..) are also covered by this logic.</p>
+ *
+ * <p>Gtk4 port note:
+ * - Note, Combo was re-written in Gtk3 and it will be re-written again in Gtk4. See:
+ * https://mail.gnome.org/archives/gtk-list/2016-December/msg00036.html
+ * https://raw.githubusercontent.com/gnome-design-team/gnome-mockups/master/theming/widgets/combobox-replacements.png // mockup screen shot.
+ * - So probably this workaround should be removed in Gtk4 port. Feel free to validate via Bug489640_SlowCombo and Bug489640_SlowComboSingleItem test snippets.</p>
+ *
+ * <p>CSS note: Do not use the CSS 'appears-as-list' style as done in:
+ * https://git.eclipse.org/r/#/c/117681/6/bundles/org.eclipse.swt/Eclipse+SWT/gtk/org/eclipse/swt/widgets/Combo.java
+ * It's a poorly working hack. If list has more than +-1000 entries, then we get visual cheese and jvm crashes. </p>
+ */
+private void gtk_combo_box_toggle_wrap (boolean wrap) {
+ if (handle == 0) return;
+ if (GTK.GTK3) {
+ if (!wrap) {
+ if (GTK.gtk_combo_box_get_wrap_width(handle) == 1) {
+ GTK.gtk_combo_box_set_wrap_width(handle, 0);
+ }
+ } else {
+ if (delayedEnableWrap) {
+ return;
+ } else {
+ delayedEnableWrap = true;
+ display.asyncExec(() -> {
+ if (!isDisposed() && handle != 0) {
+ GTK.gtk_combo_box_set_wrap_width(handle, 1);
+ delayedEnableWrap = false;
+ }
+ });
+ }
+ }
+ } else { // GTK2
+ if (wrap) {
+ GTK.gtk_combo_box_set_wrap_width(handle, 1);
+ } else {
+ GTK.gtk_combo_box_set_wrap_width(handle, 0);
+ }
+ }
+}
+
/**
* Adds the listener to the collection of listeners who will
* be notified when the receiver's text is modified, by sending
@@ -458,8 +523,7 @@ void createHandle (int index) {
if (handle == 0) error (SWT.ERROR_NO_HANDLES);
cellHandle = GTK.gtk_bin_get_child (handle);
if (cellHandle == 0) error (SWT.ERROR_NO_HANDLES);
- // Setting wrap width has the side effect of removing the whitespace on top in popup bug#438992
- GTK.gtk_combo_box_set_wrap_width(handle, 1);
+ gtk_combo_box_toggle_wrap(true);
} else {
handle = GTK.gtk_combo_box_text_new_with_entry();
if (handle == 0) error (SWT.ERROR_NO_HANDLES);
@@ -1766,9 +1830,12 @@ public void remove (int start, int end) {
items = newItems;
int index = GTK.gtk_combo_box_get_active (handle);
if (start <= index && index <= end) clearText();
+
+ if (GTK.GTK3) gtk_combo_box_toggle_wrap(false);
for (int i = end; i >= start; i--) {
if (handle != 0) GTK.gtk_combo_box_text_remove(handle, i);
}
+ if (GTK.GTK3) gtk_combo_box_toggle_wrap(true);
}
/**
@@ -1810,7 +1877,7 @@ public void removeAll () {
items = new String[0];
clearText ();
if (GTK.GTK3) {
- if (handle != 0) GTK.gtk_combo_box_text_remove_all(handle);
+ gtk_combo_box_text_remove_all();
} else {
for (int i = count - 1; i >= 0; i--) {
if (handle != 0) GTK.gtk_combo_box_text_remove (handle, i);
@@ -2105,14 +2172,11 @@ public void setItem (int index, String string) {
error (SWT.ERROR_INVALID_ARGUMENT);
}
items [index] = string;
- byte [] buffer = Converter.wcsToMbcs (string, true);
- if (GTK.GTK3) {
- if (handle != 0) GTK.gtk_combo_box_text_remove (handle, index);
- if (handle != 0) GTK.gtk_combo_box_text_insert (handle, index, null, buffer);
- } else {
- if (handle != 0) GTK.gtk_combo_box_text_remove (handle, index);
- if (handle != 0) GTK.gtk_combo_box_text_insert_text (handle, index, buffer);
+ if (handle != 0) {
+ GTK.gtk_combo_box_text_remove (handle, index);
}
+ gtk_combo_box_insert(string, index);
+
if ((style & SWT.RIGHT_TO_LEFT) != 0 && popupHandle != 0) {
GTK.gtk_container_forall (popupHandle, display.setDirectionProc, GTK.GTK_TEXT_DIR_RTL);
}
@@ -2143,7 +2207,7 @@ public void setItems (String... items) {
System.arraycopy (items, 0, this.items, 0, items.length);
clearText ();
if (GTK.GTK3) {
- if (handle != 0) GTK.gtk_combo_box_text_remove_all(handle);
+ gtk_combo_box_text_remove_all();
} else {
for (int i = count - 1; i >= 0; i--) {
if (handle != 0) GTK.gtk_combo_box_text_remove (handle, i);
@@ -2151,18 +2215,19 @@ public void setItems (String... items) {
}
for (int i = 0; i < items.length; i++) {
String string = items [i];
- byte [] buffer = Converter.wcsToMbcs (string, true);
- if (GTK.GTK3) {
- if (handle != 0) GTK.gtk_combo_box_text_insert (handle, i, null, buffer);
- } else {
- if (handle != 0) GTK.gtk_combo_box_text_insert_text (handle, i, buffer);
- }
+ gtk_combo_box_insert(string, i);
if ((style & SWT.RIGHT_TO_LEFT) != 0 && popupHandle != 0) {
GTK.gtk_container_forall (popupHandle, display.setDirectionProc, GTK.GTK_TEXT_DIR_RTL);
}
}
}
+private void gtk_combo_box_text_remove_all() {
+ gtk_combo_box_toggle_wrap(false);
+ if (handle != 0) GTK.gtk_combo_box_text_remove_all(handle);
+ gtk_combo_box_toggle_wrap(true);
+}
+
/**
* Marks the receiver's list as visible if the argument is <code>true</code>,
* and marks it invisible otherwise.

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