Think Python - Denison University

184 Chapter 19. Casestudy: Tkinter19.4 CoordinatesequencesTherectanglemethodtakesasequenceofcoordinatesthatspecifyoppositecornersoftherectangle.Thisexampledrawsagreenrectanglewiththelowerleftcornerattheoriginandtheupperrightcorner at (200,100):canvas.rectangle([[0, 0], [200, 100]],fill='blue', outline='orange', width=10)Thiswayofspecifyingcornersiscalledaboundingboxbecausethetwopointsboundtherectangle.ovaltakes a bounding box and draws an oval withinthespecified rectangle:canvas.oval([[0, 0], [200, 100]], outline='orange', width=10)linetakesasequenceofcoordinatesanddrawsalinethatconnectsthepoints. Thisexampledrawstwolegs ofatriangle:canvas.line([[0, 100], [100, 200], [200, 100]], width=10)polygontakesthesamearguments,butitdrawsthelastlegofthepolygon(ifnecessary)andfillsitin:canvas.polygon([[0, 100], [100, 200], [200, 100]],fill='red', outline='orange', width=10)19.5 MorewidgetsTkinter provides two widgets that let users type text: an Entry, which is a single line, and a Textwidget, which has multiplelines.encreates a new Entry:entry = g.en(text='Default text.')Thetextoptionallowsyoutoputtextintotheentrywhenitiscreated. Thegetmethodreturnsthecontents of theEntry (which mayhave been changed by theuser):>>> entry.get()'Default text.'tecreates a Text widget:text = g.te(width=100, height=5)widthandheightarethedimensions of the widget incharacters and lines.insertputs text intotheText widget:text.insert(END, 'A line of text.')ENDisaspecial index that indicates the lastcharacter inthe Text widget.You can also specify a character using a dotted index, like 1.1, which has the line number beforethe dot and the column number after. The following example adds the letters 'nother' after thefirstcharacter of thefirstline.