platform/platform-api/src/com/intellij/ui/components/JBTextField.java

/*
 * Copyright 2000-2012 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.intellij.ui.components;

import com.intellij.util.ui.ComponentWithEmptyText;
import com.intellij.util.ui.StatusText;
import com.intellij.util.ui.UIUtil;
import org.jetbrains.annotations.NotNull;

import javax.swing.*;
import java.awt.*;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;

public class JBTextField extends JTextField implements ComponentWithEmptyText {
  private StatusText myEmptyText;

  public JBTextField() {
    init();
  }

  public JBTextField(int i) {
    super(i);
    init();
  }

  public JBTextField(String s) {
    super(s);
    init();
  }

  public JBTextField(String s, int i) {
    super(s, i);
    init();
  }

  private void init() {
    UIUtil.addUndoRedoActions(this);
    myEmptyText = new StatusText(this) {
      @Override
      protected boolean isStatusVisible() {
        return JBTextField.this.getText().isEmpty() && !isFocusOwner();
      }

      @Override
      protected Rectangle getTextComponentBound() {
        Rectangle b = getBounds();
        return new Rectangle(getInsets().left >> 1, 0, b.width, b.height);
      }
    };
    myEmptyText.clear();
    addFocusListener(new FocusListener() {
      @Override
      public void focusGained(FocusEvent e) {
        repaint();
      }

      @Override
      public void focusLost(FocusEvent e) {
        repaint();
      }
    });
  }

  @NotNull
  @Override
  public StatusText getEmptyText() {
    return myEmptyText;
  }

  @Override
  protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    myEmptyText.getComponent().setFont(getFont());
    myEmptyText.paint(this, g);
  }
}