feat: Add hints and tooltip for url and open jar fields

ashv/src/main/java/gui/connect/ConnectToDbArea.java

@@ -9,6 +9,7 @@
 import gui.MainTabbedPane;
 import gui.MonitorDbPanel;
 import gui.chart.ChartDatasetManager;
+import gui.custom.HintTextField;
 import gui.util.ProgressBarUtil;
 import lombok.extern.slf4j.Slf4j;
 import net.miginfocom.swing.MigLayout;
@@ -85,8 +86,8 @@ public class ConnectToDbArea extends JDialog {
     private JTextField connNameTF = new JTextField();
     private JTextField usernameTF = new JTextField();
     private JPasswordField passwordTF = new JPasswordField();
-    private JTextField urlTF = new JTextField();
-    private JTextField jarTF = new JTextField();
+    private JTextField urlTF = new HintTextField(Labels.getLabel("gui.connection.url.hint"));
+    private JTextField jarTF = new HintTextField(Labels.getLabel("gui.connection.jar.hint"));
     private JFileChooser jarFC = new JFileChooser();
     private JCheckBox isOffline = new JCheckBox();
 
@@ -193,12 +194,12 @@ private void init_gui(){
         detailJPanel.add(separatorLbl, "gapbottom 1, span, split 2, aligny center");
         detailJPanel.add(new JSeparator(), "gapleft rel, growx");
 
-
         detailJPanel.add(connNameLbl,   "skip");
         detailJPanel.add(connNameTF,    "span, growx");
 
         detailJPanel.add(urlLbl,   "skip");
         detailJPanel.add(urlTF,    "span, growx");
+        urlTF.setToolTipText(Labels.getLabel("gui.connection.url.tooltip"));
 
         detailJPanel.add(usernameLbl,   "skip");
         detailJPanel.add(usernameTF,    "span, growx");

ashv/src/main/java/gui/custom/HintTextField.java

@@ -0,0 +1,29 @@
+package gui.custom;
+
+import javax.swing.*;
+import java.awt.*;
+
+public class HintTextField extends JTextField {
+
+    public HintTextField(String hint) {
+        _hint = hint;
+    }
+
+    @Override
+    public void paint(Graphics g) {
+        super.paint(g);
+        if (getText().length() == 0) {
+            int h = getHeight();
+            ((Graphics2D)g).setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING,RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
+            Insets ins = getInsets();
+            FontMetrics fm = g.getFontMetrics();
+            int c0 = getBackground().getRGB();
+            int c1 = getForeground().getRGB();
+            int m = 0xfefefefe;
+            int c2 = ((c0 & m) >>> 1) + ((c1 & m) >>> 1);
+            g.setColor(new Color(c2, true));
+            g.drawString(_hint, ins.left, h / 2 + fm.getAscent() / 2 - 2);
+        }
+    }
+    private final String _hint;
+}

ashv/src/main/resources/messages.properties

@@ -22,6 +22,10 @@ gui.connection.password=Password
 gui.connection.url=URL
 gui.connection.profile=Profile
 
+gui.connection.url.hint=jdbc:oracle:thin:@host:PORT:SID
+gui.connection.url.tooltip=jdbc:oracle:thin:@host:PORT:SID or jdbc:postgresql://host:PORT/db
+gui.connection.jar.hint=Open JDBC Driver jar file
+
 gui.connection.jar=JAR file
 gui.connection.offline=Offline
 gui.connection.open=JAR file