(Addresses #1421)
**Behaviour description:**
* Toggle step-recording mode using the dedicated icon.
* This mode is mutually exclusive with other recoding modes (record/record
accompany).
* Step-Recording while song is playing is allowed (and fun! :) ).
* When start recording, the start recording-position will be set where the
timeline curser points (quantized backwards using PianoRoll's current
quantization). If step-recording is started while the pattern is playing the
start recording-position is set to the beginning of the pattern.
* Step length is determined by the Piano Roll's current note-length (can be
changed dynamically during step-recording).
* The record-position can be moved forward/backward using the right/left keys.
* When notes are pressed on keyboard/midi-device, they will be added
temporarily ("recorded") with a length of a step. while still pressed, user
can adjust the length by steps resolution using the arrow keys (e.g. moving
right once will make the note's length 2-steps, another right press will make
the length 3-steps etc.).
* When all pressed-keys are released, the actual recording happen and the
notes are added.
* If the user press multiple notes, and release some of them for some time
which indicates it is intentional i.e. he didn't want to do a full release
to record the step but rather just change what will be recorded (I set the
"intentional release threshold" to 70 milliseconds) - these note will be
removed from current step-recording. e.g.
* Added notes are not quantized, making the addition simpler and WYSIWYG
* Similiarly to adding notes using mouse clicks, an undo-checkpoint is added
per added step and not for the whole recording as in other record modes.
* Move implementation to a new cpp file
* Use std::vector as base class instead of doing our own memory management
* Remove unused dangerous functions
* Make more use of std algorithms
* Some cleanups in code using ValueBuffer
* play sampletracks from any song position
* take care of TCO length
* TCOs shouldn't be updated when SE window is resized
* take care of zooming level
* takes care on all song position changes and mute/solo tracks now
* playes the sample only within the buffer limits
* takes care of time signature changes
* some minor code improvements (zapashcanon)
* loopback one tick earlier
* minor code changes
* get rid off clicks by resize and scrolling song editor
* removes playhandle by remove TCO
* minor bugs on manipulating TCOs in Song Editor
* update on add sample by playing
* white spaces 1
The piano roll's actions have been grouped into several toolbars. There
are now five groups / tool bars: "Transport controls", "Note controls",
"Copy paste controls", "Timeline controls" and "Zoom and note controls"
(this group is a bit mixed). Each group can be turned off and on using
the standard toolbar context menu provided by Qt.
The new default layout of the toolbars saves horizontal space by putting
the "Zoom and note controls" below the other toolbars. The toolbars can
be hidden and shown via the context menu but these states are not
stored.
The "Song editor", "Beat+Bassline editor" and "Automation editor" have
been switched to using movable toolbars as well.
Adjusted the Editor class to have some other defaults for the "Transport
controls".
Added some methods to add toolbars to editors and changed the other
editors' code to use it. This way the properties of a standard editor
toolbar can be changed in a simple and central way.
Fixed the size of the timeline control buttons which are implemented as
NStateButton. Previously these had a fixed size and appeared smaller than
all other buttons. Now they behave like other ToolButton with respect to
the size. Also removed a fixed size call in ToolButton itself.
Made some adjustments to the CSS for QToolBar and QToolButton:
* Switched the QToolBar CSS to a vertical gradient and also increased
the padding to 2px on the way.
* Previously all buttons looked like they were pressed. This was fixed by
using the same linear gradient that is used for the QToolBar.
* The hover effect for QToolButtons is a bit more subtle now and looks
less intensive as when the button is pressed / checked.
* Gave the normal buttons a bit more radius.
* Adjusted the radii of the special play and stop buttons to be
symmetric so the do not look skewed.
