Mouse usage

Use it to

click on buttons,
change values by 1 (up/down) by clicking,
change values by clicking on a value, holding the button and moving the mouse up- or downwards, and to
move sliders.

Marks the range of a sample you want displayed. To do so, drag the mouse over the sample display while holding the mouse button.
Zooms the sample display. To do so, click on either side of the slider that shows the displayed part of the sample and move the mouse while pressing the button.
When you move mouse to any sample edge (left or right edge of screen) while marking it will start zooming the sample in that direction.
Double clicking on the scroll bar will zoom in.
Double clicking (left or right) on the sample display will mark the whole selection.

In the Pattern editor for hexadecimal numbers' explanation. Additional note: Clicking with the right button decreases the values.

In the (3) Instrument selector you can select a sample as source sample by clicking on a sample name. If you click on the number next to sample name, this selects the sample number as destination sample.
Double clicking on a sample (split) opens the Sample editor.
Double clicking on an instrument opens the VST's own editor window if the instrument is a VST instrument. Otherwise it opens the Instrument Settings and Instrument editor.

Left clicking on non-named area disables (mutes) tracks or plays tracks solo (click with the right button).
Left/right clicking on the track name area makes the cursor jump to this track.

A click loads files or changes directories.
Clicks on the Favorite buttons (1,2,3,4) bring you to the directories that were saved as favorites.

Holding a mouse button and dragging mouse marks a block.
A double click on a track's area mutes the track. Double clicking again unmutes it. The track will not be played in the mix while muted.
Clicks on a track's name area allows you to rename it. Usually tracks are given the names of the instruments playing in there.
Clicking on an arrow expands track note columns or track effect columns (there are two kings of arrows there). Clicking on an arrow in the other direction reduces columns.
Clicking on the envelope sign (only visible if an track envelope exists) opens the Track Automation menu.
If you use a multi I/O sound card, you can click on M1234 to change the routing destination.

The right mouse button mainly serves as acceleration button.
Use it for the following:

On most buttons adds / subtracts 16 dec. (10 hex.) to current value instead of 1. See the Pattern editor for an explanation of hex numbers. However, in the (1) Position editor it subtracts assigned pattern number by 1 or hex 10 (depending on which digit you chose in the Configs menu).
You can move sliders in Track DSPs with it to record effects into a track effect column or an automation curve.
Clicking on the name of sample or instrument renames it.

A right click plays a track solo (muting all other tracks). Clicking again on the same track unmutes all tracks. Press the right button on another track to play it solo.

Stores the current directory for the selected file type in the Favorites buttons.

Holding a mouse button down and dragging mouse marks a block.
A double click selects a track for solo play (mutes all other tracks). Double clicking it again unmutes all tracks.
Clicking on a track selects it. Moving the mouse up/down while pressing the button scrolls through the pattern.
CTRL + right click on a note selects the instrument that is being triggered by the note.

Holding mouse buttons for a while (how long is set up in the Configs menu will start the key repeat function.