Added API for checking if BASE_URI

The contribution provides an API to check if the location is the
location where custom texts are loaded in a browser. By construct,
"about:blank" is used for that purpose. This API can be adapted by the
clients instead of explicitly defining the string and checking.

Contributes to #213

bundles/org.eclipse.swt/Eclipse SWT Browser/common/org/eclipse/swt/browser/Browser.java

@@ -13,6 +13,8 @@
  *******************************************************************************/
 package org.eclipse.swt.browser;
 
+import java.net.*;
+
 import org.eclipse.swt.*;
 import org.eclipse.swt.widgets.*;
 
@@ -1201,4 +1203,15 @@ public void stop () {
 	checkWidget();
 	webBrowser.stop ();
 }
+
+/**
+ * Checks if the location supplied is the location for setting custom text in the browser
+ *
+ * @param location the URL to be checked
+ *
+ * @since 3.127
+ */
+public boolean isLocationForCustomText(String location) {
+	return URI.create(location).equals(webBrowser.getBaseUri());
+}
 }

bundles/org.eclipse.swt/Eclipse SWT Browser/common/org/eclipse/swt/browser/WebBrowser.java

@@ -13,6 +13,7 @@
  *******************************************************************************/
 package org.eclipse.swt.browser;
 
+import java.net.*;
 import java.util.*;
 import java.util.List;
 
@@ -36,6 +37,7 @@ abstract class WebBrowser {
 
 	static final String ERROR_ID = "org.eclipse.swt.browser.error"; // $NON-NLS-1$
 	static final String EXECUTE_ID = "SWTExecuteTemporaryFunction"; // $NON-NLS-1$
+	private static final URI BASE_URI = URI.create("about:blank");
 
 	static List<String[]> NativePendingCookies = new ArrayList<> ();
 	static String CookieName, CookieValue, CookieUrl;
@@ -724,6 +726,10 @@ public void setBrowser (Browser browser) {
 	this.browser = browser;
 }
 
+public URI getBaseUri() {
+	return BASE_URI;
+}
+
 public abstract boolean setText (String html, boolean trusted);
 
 public abstract boolean setUrl (String url, String postData, String[] headers);

examples/org.eclipse.swt.examples/src/org/eclipse/swt/examples/controlexample/BrowserTab.java

@@ -209,7 +209,7 @@ void disposeExampleWidgets () {
 		/* store the state of the Browser if applicable */
 		if (browser != null) {
 			String url = browser.getUrl();
-			if (url.length() > 0 && !url.equals("about:blank")) { //$NON-NLS-1$
+			if (url.length() > 0 && !browser.isLocationForCustomText(url)) { //$NON-NLS-1$
 				lastUrl = url;
 			} else {
 				String text = browser.getText();

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_browser_Browser.java

@@ -518,6 +518,18 @@ public void changing(LocationEvent event) {
 	for (int i = 0; i < 100; i++) browser.removeLocationListener(listener);
 }
 
+
+
+@Test
+public void test_isLocationForCustomText() {
+	AtomicBoolean changingFired = new AtomicBoolean(false);
+	browser.addLocationListener(changingAdapter(e -> changingFired.set(true)));
+	shell.open();
+	browser.setText("Hello world");
+	waitForPassCondition(changingFired::get);
+	assertTrue("LocationListener.changing() event was never fired", browser.isLocationForCustomText(browser.getUrl()));
+}
+
 @Test
 public void test_LocationListener_changing() {
 	AtomicBoolean changingFired = new AtomicBoolean(false);
@@ -1141,7 +1153,7 @@ private void validateTitleChanged(String expectedTitle, Runnable browserSetFunc)
 	shell.open();
 
 	boolean hasFinished = waitForPassCondition(() -> actualTitle.get().length() != 0
-			&& !actualTitle.get().contains("about:blank")); // Windows sometimes does 2 loads, one "about:blank", and one actual load.
+			&& !browser.isLocationForCustomText(actualTitle.get())); // Windows sometimes does 2 loads, one BASE_URI, and one actual load.
 	boolean passed = hasFinished && actualTitle.get().equals(expectedTitle);
 	String errMsg = "";
 	if (!hasFinished)