Add a MeanDepthItem that has 2 strings.

Dirk's implementation of the MeanDepth item was correct, but in order to
add the 2 strings to it ( one at the begin, one at the end ) I had to put
more stuff inside the ProfileWidget that's already packed with graphics
items.

So I created a new class MeanDepthItem that contains these 2 strings and
will get updated whenever the value changes.

I also fixed a math inconsistency where I changed RIGHT to LEFT.
(wich fixed a few text-placements, and broke others.)

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix the ZLevel value of some items.

Almost all of the items on the new profile were being painted
on the same ZLevel, so the level of awesomeness was a bit random.
This puts things on the correct spots, events on top of everything,
profile at the bottom, things in the middle.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Prepare for plotting partial pressures in the new profile

This patch makes the cartesian axis of the profile depth shrink and
(together with it) the Profile Depth and the grid lines. There will
probabla bey a lot of things that didn't have their correct position
fixed, so I'll fix them in the later commits.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Simplify the code for the reported ceiling.

The reported ceiling now behaves better by not being deleted / recreated,
instead it uses the same object and connects to the model to know when to
regenerate its plot.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Do not delete / new object that can be cached.

This way we will always have this object on screen, and as soon as the
model changes, it's contents will change.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Make the tissues be preferences-aware.

This patch adds a new class DiveCalculatedTissue that's preferences aware.
It knows when to show or hide itself.

Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>