The box that displays the text of the active clip is a full-featured edit control. In fact, it is the same edit control that powers EditPad, one of the most flexible and convenient text editors available today (see https://www.editpadpro.com).
Below you can find a list of action you can carry out in the editor using the mouse.
Dragging means to move the mouse before releasing the mouse button you pressed. If you move the mouse pointer to the edge of the editor space while dragging, the text will start to scroll automatically.
Modifier keys like shift or control must be pressed before pressing the mouse button and kept depressed until the mouse button is released.
Left click Moves the text cursor to the spot where you clicked.
Shift+Left click Moves the text cursor and expands or shrinks the selection.
If there is no selection, the text between the old and new cursor positions becomes selected.
If you click outside of the selection, the selection plus the text between the selection and the new cursor position becomes selected.
If you click inside the selection, the new selection is the text between the original start of the selection and the new cursor position.
Left click+drag When clicking outside the selection, a new selection is created from the point where you press the mouse button until the point where you release it.
When clicking inside the selection, the selected text deleted and inserted again at the spot (outside the selection) where you release the mouse button.
Shift+Left click+drag Expands or shrinks the selection like Shift+Left click, but then the text cursor is moved and the selection adjusted until you release the mouse button.
Rotate wheel Scrolls the text a single line up or down.
Shift+Wheel Moves the text cursor a line up or down, like pressing the up or down arrow keys on the keyboard.
Ctrl+Wheel Scrolls the text an entire screen up or down.
Shift+Ctrl+Wheel Moves the text cursor a screen up or down, like pressing page up or down on the keyboard.