... when you shrink a sub-view then toggle it, or toggle all views off then
exit multi-view
Fix it by making GetSubViews more robust to contents of mPlacements
... because that will be needed for elimination of some GetActiveProject()
calls. Because some overrides need to find the focused track, but that may
mutate the project by setting the focused track when it wasn't yet defined.
... When it's off (default), Spectrum and Waveform buttons behave as before,
and dragging of the sub-view separator is disabled.
When it transitions to off, and the view is split, then the top sub-view takes
up the whole view.
When it transitions on, nothing visible happens.
When it is on, and you choose Spectrum or Waveform, then the corrsponding
sub-view toggles visibility.
When a sub-view is turned on by the menu item, it appears lowest.
- There are two new commands: Scrub Backwards and Scrub Forwards.
- These commands appear on the Transport sub menu of the Extra menu.
- The commands have default shortcuts U and I, and are in the standard default set.
- After pressing one of the two keys, playback continues until the key is released. (Note that this means that the command on the Extra > Transport menu can't actually be used for scrubbing as it executes a KeyDown immediately followed by a KeyUp, but the menu items are needed so that the current keystrokes can be seen and changed.)
- Playback starts from the cursor position, or the start of a time selection if there is one.
- The speed of playback is determined by the zoom level. If the zoom level is normal, then the playback speed is one quarter of the normal playback speed. Zooming in (Ctrl + 1), halves the playback speed, and zooming out (Ctrl + 3) doubles the playback speed. There are minimum and maximum playback speeds of one sixteenth, and four respectively.
- You can scrub to the end of the audio, even if there is an initial selection. In other words, scrubbing forwards does not automatically stop at the end of the selection.
- Normally, when one of the keys is released, the position of the cursor is set to the time when the key was released.
- If during the time one of the keys is pressed the left bracket and or right bracket keys are pressed to set the start and/or end of the selection, then when the scrubbing key is released, the change to the selection made by pressing the bracket keys is preserved - the position of the cursor is not set to the time when the key was released.
This implementation is affected by two existing bugs:
1. Bug 1954 - Clicks may occur starting/pausing play-at-speed or Scrub. (See comment 19 and attached image).
2. Bug 1956 - Windows: MME and WDS playback cursor is buffer length ahead of actual audio playing. This means that on Windows, WASAPI is preferable if scrubbing is being used for the accurate positioning of the cursor.
... in cases of "TranslatableString" that are not really translated.
This makes it easier to scan the code for such unusual constructions of
TranslatableString, distinct from mere mentions of the TranslatableString type.
