[Audacity-devel] Ruler play region support added

[Markus M. <me...@me...>]

Hi everyone,

the following functionality has now been commited:

* The ruler shows the current "play region" using a gray arrow like
this: |<----->| When no region is selected only the first arrow is shown
like this: |<

* When something is selected, the play region arrow in the ruler is
updated to match the selection

* When "Play" is selected, the current region is played

* You can click into the ruler. This starts playing from the clicked
point. The selection is not affected by this.

* You can click/drag into the ruler. This effectively creates a new play
region and plays it back. The selection is not affected by this.

* You can drag the edges of the play region with the mouse. This will
_not_ start playing but just adjust the edges. Playing can then be
started by pressing the spacebar or the play toolbar button. The
selection is not affected by this.

* There's a new submenu in the "Edit" menu "Play Region" which allows
you to "lock" the playing region. In this case, if you do a new
selection, the play region will not be set to this new selection, but
stay the same. The play region arrow will change the color to red to
indicate that the play region is locked.

* Changing the selection while playing has been allowed again because it
is now obvious from the play region shown in the ruler what is currently
played, so there's no inconsistency anymore.

The above may sound a bit complicated but I believe it should be
intuitive as soon as you play with it. Please note also:

* The behaviour for selecting and playing has not been changed at all.
Infact, selecting and playing now works exactly like in 1.2.x (again),
as long as you don't click into the ruler.

* As long as the play region is not locked (it isn't by default) the
play region follows the selection, as it was before.

* The ability to lock the play region may look strange at first sight,
but it is very useful for some tasks. E.g., if you have a sentence in an
interview from which you want to cut some words out, you can lock the
play region to this sentence, and then edit the sentence,
selecting/deselecting, cutting/pasting stuff. While doing that, you can
always press "Space" and hear the full sentence without the need to
select it again.

Please test and let me know what you think.


Markus