FileSelector.java

package name.admitriev.jhelper.ui;

import com.intellij.openapi.fileChooser.FileChooserDescriptor;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.ui.TextBrowseFolderListener;
import com.intellij.openapi.ui.TextFieldWithBrowseButton;
import com.intellij.openapi.vfs.VirtualFile;
import name.admitriev.jhelper.generation.FileUtils;
import org.jetbrains.annotations.NotNull;

import javax.swing.*;

public class FileSelector extends TextFieldWithBrowseButton.NoPathCompletion {

	public FileSelector(Project project, String initialValue, FileChooserDescriptor descriptor) {
		super(new JTextField(initialValue));
		addBrowseFolderListener(
				new RelativePathBrowseListener(descriptor, project)
		);
		installPathCompletion(descriptor);
	}

	private static class RelativePathBrowseListener extends TextBrowseFolderListener {
		private final String basePath;

		private RelativePathBrowseListener(FileChooserDescriptor descriptor, Project project) {
			super(descriptor, project);
			basePath = project.getBasePath();
		}

		@NotNull
		@Override
		protected String chosenFileToResultingText(@NotNull VirtualFile chosenFile) {
			return FileUtils.relativePath(basePath, chosenFile.getPath());
		}

		@NotNull
		@Override
		protected String expandPath(@NotNull String path) {
			return basePath+ '/' + path;
		}
	}
}