One option for label 45º. about hellocharts-android

[lecho]

I like it but adjusting axis height will be a little tricky, right now height for horizontal axis is determined using font's ascent and descent values. For axis with rotated labels we will have to use Pythagorean triangle where hypotenuse is equal to the label's length.

[douglasjunior]

Right.
If we think that the smaller sides are equal. Only with the value of the hypotenuse we can calculate the height.
In our case, the hypotenuse would be the label length.
Something like this:

labelLength ^ 2 = smallSide ^ 2 + smallSide ^ 2
labelLength ^ 2 = 2 * ( smallSide ^ 2 )
( labelLength ^ 2 ) / 2 = ( smallSide ^ 2 )
( ( labelLength ^ 2 ) / 2 ) ^ ( 1 / 2 ) = smallSide

newHeight = smallSide
newWidth = smallSide

Example:

What is the method you are using to calculate the length of the label?

[lecho]

Right now AxisRenderer calculates maximum label width based on Axis.maxLabelsChars attribute, so it is the same for all labels in given axis because text measurement tends to be slow: AxisRenderer.java#L233

Label width is also used to determine how many labels should be visible for horizontal axis: AxesRenderer.java#L435
Maybe it will be good idea to introduce different attribute for that, for example labelSeparationCharsNumber or something like that.

[douglasjunior]

If we add the Pythagorean calculation in AxisRenderer.java#L233, would not be enough ?

For the rest of the code would work with the new width normally.

It would only be necessary to use the new height to position the axis name.

[lecho]

If we add the Pythagorean calculation in AxisRenderer.java#L233, would not be enough ?

Yea, I think that should be enough.

It would only be necessary to use the new height to position the axis name.

Yes, new height should be used for axis name baseline(if axis is not inside) and axis label height:
AxesRenderer.java#L296
AxesRenderer.java#L263

[douglasjunior]

I did some testing and found that it is possible to implement
But I found a difficulty with full chart height 😕. Now the chart need to stretch vertically as the label height. (When the label be diagonally)
I think better to wait you look when you can.

[lecho]

Ok, I will have more time next week:)

[lecho]

I had some problems with this but now it should work. Axis has method `Axis.setHasLabelTilted(boolean)', if set to true labels for that axis are rotated by -45 degrees.

[douglasjunior]

Very nice!

I will test tomorrow.

Thanks

[rasik1010]

can we start chart from right to left side? any idea about this? please help me if any one knows , thank you.