Selecting Widgets in Wireframes
Select a widget
Click on the widget with your mouse.
Select multiple widgets
Click on the first widget and hold down the Ctrl key while clicking other widgets to select and unselect them.
Another method to select multiple widgets is to press down on your mouse button while over the pane (not a widget) and drag to draw a selection rectangle. There are two modes of selection, which you can toggle between using the buttons in the editor toolbar:
Select Intersected Mode: All of the objects intersecting with the selection rectangle will be selected.
Select Contained Mode: All of the objects fully contained within the selection rectangle will be selected.
Select All
You can also select all of the objects on the editor by clicking Edit->Select All or Ctrl+A.