Prevent the user from selecting an invalid branch/reset target.

The branch selection dialog needs to enable/disable its buttons
based on what the user has selected. This will help provide a
better user experience as they will be less likely to get into a
state where an error dialog will popup on them.

Change-Id: Iec736b78204d4201a428bb2608e124d9d9e5cab1
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>

3 files changed, 16 insertions, 16 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
index 432a777d38..cac5ca9e11 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
@@ -1297,9 +1297,6 @@ public class UIText extends NLS {
 	public static String BranchSelectionDialog_LocalBranches;
 
 	/** */
-	public static String BranchSelectionDialog_NoBranchSeletectTitle;
-
-	/** */
 	public static String BranchSelectionDialog_ReallyResetTitle;
 
 	/** */
@@ -1336,9 +1333,6 @@ public class UIText extends NLS {
 	public static String BranchSelectionDialog_OkCheckout;
 
 	/** */
-	public static String BranchSelectionDialog_NoBranchSeletectMessage;
-
-	/** */
 	public static String BranchSelectionDialog_Refs;
 
 	/** */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/BranchSelectionDialog.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/BranchSelectionDialog.java
index b841b91cb2..802922c382 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/BranchSelectionDialog.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/BranchSelectionDialog.java
@@ -32,6 +32,7 @@ import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.DisposeEvent;
 import org.eclipse.swt.events.DisposeListener;
+import org.eclipse.swt.events.SelectionAdapter;
 import org.eclipse.swt.events.SelectionEvent;
 import org.eclipse.swt.events.SelectionListener;
 import org.eclipse.swt.graphics.Font;
@@ -86,6 +87,8 @@ public class BranchSelectionDialog extends Dialog {
 
 	private Tree branchTree;
 
+	private Button confirmationBtn;
+
 	@Override
 	protected Composite createDialogArea(Composite base) {
 		parent = (Composite) super.createDialogArea(base);
@@ -93,6 +96,15 @@ public class BranchSelectionDialog extends Dialog {
 		new Label(parent, SWT.NONE).setText(UIText.BranchSelectionDialog_Refs);
 		branchTree = new Tree(parent, SWT.BORDER);
 		branchTree.setLayoutData(GridDataFactory.fillDefaults().grab(true,true).hint(500, 300).create());
+		branchTree.addSelectionListener(new SelectionAdapter() {
+			@Override
+			public void widgetSelected(SelectionEvent e) {
+				// calculate the user's selected ref
+				refNameFromDialog();
+				// make sure it's a valid selection
+				confirmationBtn.setEnabled(refName != null);
+			}
+		});
 
 		if (showResetType) {
 			buildResetGroup();
@@ -252,13 +264,6 @@ public class BranchSelectionDialog extends Dialog {
 	@Override
 	protected void okPressed() {
 		refNameFromDialog();
-		if (refName == null) {
-			MessageDialog.openWarning(getShell(),
-					UIText.BranchSelectionDialog_NoBranchSeletectTitle,
-					UIText.BranchSelectionDialog_NoBranchSeletectMessage);
-			return;
-		}
-
 		if (showResetType) {
 			if (resetType == ResetType.HARD) {
 				if (!MessageDialog.openQuestion(getShell(),
@@ -414,10 +419,13 @@ public class BranchSelectionDialog extends Dialog {
 				}
 			});
 		}
-		createButton(parent, IDialogConstants.OK_ID,
+		confirmationBtn = createButton(parent, IDialogConstants.OK_ID,
 				showResetType ? UIText.BranchSelectionDialog_OkReset
 						: UIText.BranchSelectionDialog_OkCheckout, true);
 		createButton(parent, IDialogConstants.CANCEL_ID, IDialogConstants.CANCEL_LABEL, false);
+
+		// can't advance without a selection
+		confirmationBtn.setEnabled(branchTree.getSelectionCount() != 0);
 	}
 
 	@Override
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
index 732e609d25..1f48441561 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
@@ -467,8 +467,6 @@ BranchSelectionDialog_ErrorRenameFailed=Rename failed
 
 BranchSelectionDialog_LocalBranches=Local Branches
 BranchSelectionDialog_NewBranch=&New branch
-BranchSelectionDialog_NoBranchSeletectMessage=You must select a valid ref.
-BranchSelectionDialog_NoBranchSeletectTitle=No branch/tag selected
 BranchSelectionDialog_OkCheckout=&Checkout
 BranchSelectionDialog_OkReset=&Reset
 BranchSelectionDialog_QuestionNewBranchMessage=Enter name of new branch. It will branch from the selected branch. refs/heads/ will be prepended to the name you type