__References__:
Issues: https://musescore.org/en/node/19155https://musescore.org/en/node/22861https://musescore.org/en/node/23100
__Description__:
Allows to change the start and end note to which a glissando is anchored after it has been entered. Either anchor can be changed independently.
The user interface follows the current working of other 'snappable' lines. Once either the start or end grip is selected:
- `[Shift]+[Left]` snaps the anchor to the previous chord, defaulting to its top note.
- `[Shift]+[Right]` snaps to the next chord, defaulting to its top note.
- `[Shift]+[Up]` snaps to the note above (possibly in a chord, voice or staff above the current one).
- `[Shift]+[Down]` snaps to the note below (possibly in a chord, voice or staff below the current one).
This permits to set the anchor points of a glissando to any note in the score, allowing several glissandi between the notes of the same two chords and other complex configurations (glissandi skipping intermediate chords, start and end notes in different voices or staves, and so on).
It is possible to move the anchor to a different staff of the same instrument, but not to a different instrument; also, it is not possible to 'cross' a change of instrument in the same staff.
__Known limitations__:
- The `[Shift]+[Up]` and `[Shift]+[Down]` use the same note-finding functions as the `[Alt]+[Up]` and `[Alt]+[Down]`actions which move the selection cursor to the above and below note, even across voices or staves. Occasionally, in particular if the note immediately above or below is not time-aligned, the algorithm has little expected results; however, the behaviour is already known to the user. Improving the algorithm would benefit both uses.
__Notes__:
- Most of the added infrastructure is not specific to glissando but to any spanner anchored to notes, then it should also add after-the-fact "snap to" note support to note-anchored text line.
- When moving an anchor, the algorithm usually prefers a note in the same voice/staff of the old note if it exists; if there is none, it tries other voices of the same staff.
- The change of anchor is undoable.
- The fix corrects the management of the `Chord::_endsGlissando` flag, taking into account that a chord can be the ending point of several glissandi and removing one of them not necessarily means the chord no longer ends a glissando (another glissando may still exists).
- The fix also improved the rendering of the glissando wavy line, with better alignment with anchor notes and, with glissando text, better text-line spacing.
- Implemented as a sub-class of `SLine`.
- Anchor type changed from CHORD to NOTE: allows to attach glissando start and end points to individual notes, rather than generically to chords (with note within the chord chosen by the program).
- The Glissando element is now stored in the `Note::_spannerFor` list.
- `Chord::_glissando` has been removed and replaced by a `bool _endsGlissando`, recording whether the chord is at the end of glissando (as gliss.-end chords require more space if mid-measure or system-initial).
- Debugger UI for `Chord` updated accordingly.
- Glissando in now save into score file as a spanner, within the initial note, and with appropriate `<endSpanner>` tag in the Glissando ending note.
- Existing scores with the old Glissando file format are correctly read back.
Notes:
- MusicXML import/export of the new Glissando implementation NOT IMPLEMENTED.
- This version can read scores from older versions, but older versions **cannot read** scored from this version (they do not expect a <Glissando> tag within a Note). Does this require a NEW FILE VERSION NUMBER?
- This implementation would allow rather easily to move the start and end anchors around (as for slurs) to override the note/chord chosen by the program when the glissando is initially created; but the UI for this is not implemented yet.
When a syll. dash is too short to fit between two syllables, it is skipped. This looks badly at system end, where room for a short dash is usually available within the note-to-barline distance + barline width.
With this patch, a syll. dash at the end of a system is always drawn with at least the shortest acceptable length (or more, if more room is available), even if under normal conditions it would not fit. In a position where the in-word status of a syllable is not easy to guess, the occasional dash (very) slightly extending beyond the bar line seems more acceptable that no dash at all.
This patch also limits the `LyricsLine`-specific correction in `SLine::linePos()` to melisma only, using common processing for syllabic dash lines.
The melisma line had an undershooting length correction; with the latest change, it is now too short.
Correction changed to overshoot the chord by `minNoteDistance`, as it is definitely less massive than the chord itself.
Also removed a useless test in `line.cpp`.
Implements melisma and dash lines for lyrics spanning several systems.
The melisma and dash line is based on the `SLine` class and its segments on the `LineSegment` class. Both the whole line and its segments are not selectable, marked as generated and not saved in the score file, which is not changed in any way.
For very wide dash segments, several dashes are drawn; the distance between the dashes is not configurable.
Lyrics layout code in `Measure` class and in `layout.cpp` file has been commented out as the lyrics line layout is all contained in the lyrics.cpp file
The line is registered with the `Score` (to have its layout delayed until all elements are positioned) with a mechanism similar to other `Spanner`'s, but in a different container (`_unmanagedSpanner`), as the owning `Lyrics` should decide when create, register, unregister and delete its line.
The line segments are registered with the `System` they belong to (to have them drawn), in the same way as other `Spanner`'s.
There is code for using the dash metrics of the lyrics font, but it is turned off via a conditional directive, as there does not seem to be a reliable way to determine the dash metrics; conventional values (determined by trials and errors and based on my taste!) are used when the conditional directive is off.
