Bug 80833 [Import/Export] Import exisiting should pre-check for project already in workspace
While it is good that it lets you import projects in the default workspace location, it should not let you select projects that already exist in the workspace (since importing such a project will fail). When searching for .project files in the file system, it could use IWorkspaceRoot.findFilesForLocation followed by checking IFile.exists() to filter out .project files for existing projects.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
IDialogSettings settings = getDialogSettings();
        if (settings != null) {
            	
            copyCheckbox.setSelection(settings
                    .getBoolean(STORE_COPY_PROJECT_ID));
        }
        copyFiles = copyCheckbox.getSelection();
    }
    /**
     * 	Since Finish was pressed, write widget values to the dialog store so that they
     *	will persist into the next invocation of this wizard page.
     *
     *	Method declared public only for use of tests.
     */
    public void saveWidgetValues() {
        IDialogSettings settings = getDialogSettings();
        if (settings != null) {
            settings.put(STORE_COPY_PROJECT_ID,
                    copyCheckbox.getSelection());
        }
    }
    /**
     * Method used for test suite.
     * @return Button copy checkbox
     */
	public Button getCopyCheckbox() {
		return copyCheckbox;
	}    
}