full circle magazine #65

HOWTO - PROGRAMMING IN PYTHON 37

You can see that this routine is

pretty self explanatory. We use a

variable (self.whichway) to

determine “which way” the labels

are displaying... from Guitar to

Piano or Piano to Guitar.

Be sure to save your work at

this point, since we are going to be

making a lot of changes from here

on.

Replace the lines defining text1

and text two with the lines shown

above.

We set self.whichway to 0 which

will be our default for the swap

procedure. Then we define four

strings instead of the two we had

last time. You might notice that

strings text3 and text4 are simple

reversals of text1 and text2.

Now we will tweak the root line

definition. Change it from...

root =

GridLayout(orientation= ' v e r t i

cal', spacing=10,

cols=1,rows=3)

root =

GridLayout(orientation= ' v e r t i

cal', spacing=6, cols=1,

rows=4,

row_default_height=40)

We’ve changed the spacing

from 10 to 6 and set the default

row height to 40 pixels. Change the

text for the label (next line) to

“text='Transposer Ver 0.8.0'”.

Everything else stays the same on

this line.

Now change the button

definition line from...

btn1 = Button(text = " " +

text1,size=(680,40),

size_hint=(None,None),

halign='left',

font_name='data/fonts/D r o i d S a

nsMono.ttf',

padding=(20,20))

to:

btn1 = Button(text = " "

+ self.text1,size=(780,20),

size_hint=(None, None),

halign='left',

font_name='data/fonts/D r o i d S a

nsMono.ttf',

padding=(20,2),

background_color=[0.39, 0 . 0 7 , .

92,1])

Notice that I’ve changed the

formatting of the first definition

for clarity. The big changes are the

size change from 680,40 to 780,20

and the background color for the

button. Remember, we can change

the background color for buttons,

not “standard” labels.

Next, we will define three

AnchorLayout widgets for the

three buttons that we will add in

later. I named th e m al0

(AnchorLayout0), al1 and al2. We

also add the code for the About

Popup, and define our buttons

along with the bind statements.

This is shown on the next page, top

left.

Find the “s = GridLayout” line

and change the spacing from 10 to

4. Next, add the following line

after the s.bind line (right before

the for loop):

LoadLabels(0)

This calls the LoadLabels

routine with our default “which” of

Next, comment out the entire

for loop code. This starts with “for i

in range(0,19):” and ends with

“s.add_widget(btn)”. We don’t

need this since the LoadLabels

routine does this for us.

self.whichway=0

self.text1 = " C | B |A#/Bb| A |G#/Ab| G |F#/Gb| F | E |D#/Eb| D |C#/Db| C |"

self.text2 = " C | B |A#/Bb| A |G#/Ab| G |F#/Gb| F | E |D#/Eb| D |C#/Db| C | B |A#/Bb | A | G # / A b | G | F # / G b | F | E | D # / A b | D | C # / D b | C | "

self.text3 = " C |C#/Db| D |D#/Eb| E | F |F#/Gb| G |G#/Ab| A |A#/Bb| B | C |"

self.text4 = " C |C#/Db| D |D#/Eb| E | F |F#/Gb| G |G#/Ab| A |A#/Bb| B | C |C#/Db | D | D # / E b | E | F | F # / G b | G | G # / A b | A | A # / B b | B | C | C # / D b | "