Reflection of class on Nov 29th

  At the beginning of this chapter 5, there is a similar interface of drawing app which I have created in last class, but the difference is that a line of various buttons is added below the bottom of the original surface. So what are these buttons used for?

  As the basic instructions of this chapter says, these buttons can change the line color and line thickness by attaching functions to them instead of key presses, and the size of these buttons can be adjusted easily as well. So how to do that?

  In order to save time, I downloaded the source code from the dedicated coding website and copied them to the new text editing interface, what I need to do is adding relative codes to the preset blanks which were highlighted by red color and run the whole procedure to see what will happen on the app canvas. Absolutely, I need try to change some codes to customize my own app canvas.

  I defined some new functions about line colors and bind them with relative keys by implementing ‘window.bind’ statement just like the last chapter. Then, following to the steps of the example, I added buttons to my application by typing codes of loading images for buttons and attached functions which include necessary variables to buttons.

  I didn’t understand completely why I need to remove ‘event’ from between the brackets of pen color functions so that the procedure could work normally, but I found that I couldn’t change the pen color by pressing preset keys anymore when I run the program. Actually, I found the solution for this item from the later content of this chapter, all I need to do was removing these useless codes from the procedure because their functions were already replaced by codes of buttons. Well, I got a feel suddenly that the author was a fantastic magician who could read my mind and predict my behavior. Just for fun.

  At last, I did the same operation as color button to plus and minus button to change line size and try to change the value of side from LEFT to RIGHT of ‘Button’ function to see what could be changed when I run it as the idea 1 said. Well, all things are correct except the position of buttons. These buttons were arranged from the right side of the bottom of the canvas. What’s more, I added another button to choose a random color which I preset before by implementing random import and ‘random.randint’ command.

  All is well! Now I can draw more fabulous images by my new drawing application!