Add WebKitBrowser seach native methods

[trancexpress]

See: eclipse-platform/eclipse.platform#1890

Since we'll need to use WebKitBrowser native API for searching, it will be useful to add the respective native methods with a preliminary PR. By doing this, maintainers who review a PR for eclipse-platform/eclipse.platform#1890 wont need to compile native libraries locally.

[trancexpress]

Example very rudimentary search after adding the native methods:

diff --git a/bundles/org.eclipse.swt/Eclipse SWT WebKit/gtk/org/eclipse/swt/browser/WebKit.java b/bundles/org.eclipse.swt/Eclipse SWT WebKit/gtk/org/eclipse/swt/browser/WebKit.java
index 5b03fc50f4..a8a10b9be1 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT WebKit/gtk/org/eclipse/swt/browser/WebKit.java        
+++ b/bundles/org.eclipse.swt/Eclipse SWT WebKit/gtk/org/eclipse/swt/browser/WebKit.java        
@@ -25,6 +25,7 @@ import java.util.concurrent.atomic.*;
 import java.util.function.*;
 
 import org.eclipse.swt.*;
+import org.eclipse.swt.events.*;
 import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.internal.*;
 import org.eclipse.swt.internal.gtk.*;
@@ -784,6 +785,12 @@ public void create (Composite parent, int style) {
                                onResize (event);
                                break;
                        }
+                       case SWT.KeyDown: {
+                               if (event.keyCode == 'f' && (event.stateMask & SWT.CTRL) == SWT.CTRL) {
+                                       openSearchDialog();
+                               }
+                               break;
+                       }
                }
        };
        browser.addListener (SWT.Dispose, listener);
@@ -2665,6 +2672,53 @@ private void webkit_settings_set(byte [] property, int value) {
        OS.g_object_set(settings, property, value, 0);
 }
 
+private void openSearchDialog() {
+       Shell shell = new Shell(browser.getShell());
+       shell.setText("Search for text");
+       shell.setLayout(new FillLayout());
+       shell.setSize(400, 100);
+       Composite c = new Composite(shell, SWT.NONE);
+       GridLayout l = new GridLayout();
+       l.numColumns = 3;
+       c.setLayout(l);
+       Text t = new Text(c, SWT.BORDER);
+       Button n = new Button(c, SWT.BORDER);
+       n.setText("Next");
+       Button p = new Button(c, SWT.BORDER);
+       p.setText("Prev");
+
+       long findController = WebKitGTK.webkit_web_view_get_find_controller(webView);
+       AtomicBoolean searched = new AtomicBoolean(false);
+       n.addSelectionListener(new SelectionAdapter() {
+               @Override
+               public void widgetSelected(SelectionEvent e) {
+                       if (!searched.getAndSet(true)) {
+                               searchText(findController, t::getText);
+                               p.setEnabled(true);
+                       } else {
+                               WebKitGTK.webkit_find_controller_search_next(findController);
+                       }
+               }
+       });
+       p.addSelectionListener(new SelectionAdapter() {
+               @Override
+               public void widgetSelected(SelectionEvent e) {
+                       WebKitGTK.webkit_find_controller_search_previous(findController);
+               }
+       });
+       p.setEnabled(false);
+       shell.addDisposeListener(e -> {
+               WebKitGTK.webkit_find_controller_search_finish(findController);
+       });
+       shell.pack();
+       shell.open();
+}
+
+private void searchText(long findController, Supplier<String> textGetter) {
+       String text = textGetter.get();
+       WebKitGTK.webkit_find_controller_search(findController, text.getBytes(), 0, 1000); // TODO: how to set no max count here?
+}
+
 static Object convertToJava (long ctx, long value) {
        int type = WebKitGTK.JSValueGetType (ctx, value);
        switch (type) {

Test with snippet:

package test.browser;

import org.eclipse.swt.SWT;
import org.eclipse.swt.browser.Browser;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

public class TestBrowser {

	public static void main(String[] args) throws InterruptedException {
		Display display = new Display();
		Shell shell = new Shell(display);
		shell.setSize(600, 800);
		shell.setLayout(new FillLayout());
		shell.setText("Test Browser");

		Browser b = new Browser(shell, SWT.NONE);
		b.setText(
				"""
				<html>
				 <head>
				 </head>
				 <body>
				   Hello World
				   <h1>Hello World</h1>
				   <p>Hello World</p>
				 </body>
				</html>
				""");

		shell.open();

		while (!shell.isDisposed()) {
			if (!display.readAndDispatch())
				display.sleep();
		}
		display.dispose();
	}

}

See screen recording:
gh1890_example_search_dialog.webm

We can discuss details on eclipse-platform/eclipse.platform#1890 or its PR, once available. The above is just a proof of concept, i.e. that its enough to add the native methods in the diff here, to make some basic searching work.

[github-actions]

Test Results

   545 files  ±0     545 suites  ±0   27m 32s ⏱️ -11s
 4 399 tests ±0   4 381 ✅ ±0   18 💤 ±0  0 ❌ ±0 
16 723 runs  ±0  16 583 ✅ ±0  140 💤 ±0  0 ❌ ±0 

Results for commit 898b732. ± Comparison against base commit d2cb26d.

[akurtakov]

It's fine to add the bindings like that as a prep step.

[trancexpress]

Thank you @akurtakov !