☰ Contents · Computing

Graphics, animation and the final test

Lessons 65–67 · 3 lessons · N. I. Taylaqov (general editor), A. B. Akhmedov, M. D. Pardayeva, A. A. Abdug‘aniyev, U. M. Mirsanov. Informatics and Information Technologies, Grade 10, 1st edition. “Extremum-Press”, Tashkent, 2017
67

Test work

Textbook: p. 154
GoalCompletes the final test on the Delphi chapter: the environment, window and button, Label, Edit, choice objects, Memo, graphics and Timer.
New words
final test: a test that covers a whole chapter · yakuniy nazoratrevision questions: questions that go over every topic of the chapter · takrorlash savollariobject–property–event: the three parts of every visual task · obyekt–xossa–hodisaself-assessment: judging your own result by a clear list of criteria · o‘z-o‘zini baholash
Explanation

The final test checks all topics of the chapter. Analyse every task with the chain “object – property – event”: which object is needed (Button, Label, Edit, RadioGroup, Memo, Image, Timer), which of its properties must be set (Caption, Text, Items, ItemIndex, Interval) and in which event the code runs (OnClick, OnCreate, OnTimer). In code analysis keep a table of the variables, and check coordinate and time calculations with a formula (the interval is in ms, 1 s = 1000 ms; the limits of Rectangle and Ellipse). For revision use the following list of topics: the stages of programming; the Delphi environment; Form and Button; ShowMessage and IntToStr; Label; Visible and Enabled; Edit and type changes; CheckBox; RadioGroup; ListBox and ComboBox; Memo; Canvas; Timer; animation. When finished, judge your result by the criteria and practise the weak topics again.

Worked examples
Sample: 1) var i, s: Integer; begin s := 0; for i := 1 to 10 do if i mod 3 = 0 then s := s + i; ListBox1.Items.Add(IntToStr(s)); end; – i = 3, 6, 9 are added: s = 18. 2) Timer Interval = 250, 10 events: 10·250 = 2500 ms = 2.5 s.
3) Image1.Canvas.Rectangle(10, 20, 110, 70) – width 100, height 50, area 100·50 = 5000 square pixels. 4) Choose the object: “a test question with one answer” – RadioGroup; “a multi-line result” – Memo; “a countdown” – Timer and Label. 5) Votes 3, 2, 1 (6 in all): the angles are 180°, 120°, 60°.
Class activity

“The rating table”: each student marks each of the 14 revision topics in the list as “I know / partly / I will revise” and writes a practice plan for the 3 weakest topics.

Practice
1
What is s after for i := 1 to 10 do if i mod 3 = 0 then s := s + i;?
2
How many seconds do 10 events with Interval = 250 last?
3
What is the area of Rectangle(10, 20, 110, 70) (in square pixels)?
4
Why is the “object – property – event” chain useful in analysing a task?