Class: ClockView

• Inheritance
• Description
• Related information
• Instance protocol
  • accessing
  • drawing
  • events
  • initialization
  • misc
  • user actions
• Demonstration
• Examples

Inheritance:

   Object
   |
   +--GraphicsMedium
      |
      +--DisplaySurface
         |
         +--SimpleView
            |
            +--ClockView

Package:

stx:libwidg3

Category:

Views-Fun

Version:

rev: 1.40 date: 2019/05/06 08:21:45

user: cg

file: ClockView.st directory: libwidg3

module: stx stc-classLibrary: libwidg3

Author:

Claus Gittinger (spring 91)

Description:

xclock replacement

:-) not that I thought this clock is any better than xclock
    or that the world needs clocks ...

its showing how easy it is to program in Smalltalk - 
this took less than an hour to program - compare with xclock code ....

Since this is a subclass of view, you can use it as a widget in
more complex views.


Implementation note:
     this class was written long before multiple threads came to ST/X;
     therefore, it uses the Processors timedBlock facilities.
     Today, things would be written differently.
     As an excercise, you may rewrite it using an update process which 
     runs in the background.

Related information:

    Clock
    RoundClock
    Time
    ProcessorScheduler

Instance protocol:

 beStopWatch

 startMeasure

 displayCenteredString: aString

 drawArm: tick width: w len: l

draw an arm of the clock; argument tick specifies minute (0..59);
width is width in pixel, len is relative len - 1.0 is full

 drawArmsFor: aTime

draw arms for a given time in current paint

 redraw

redraw everything

 redrawArms

redraw the arms

 redrawStopWatchInfo

 redrawTicks

redraw the ticks

 redrawTimeFraction

 showTime

executed every second (by timedBlock)

 timeShown

 updateArms

clear previous arms - draw new arms

 updateArmsFor: aTime

clear previous arms - draw new arms

 buttonPress: button x: x y: y

 keyPress: key x: x y: y

 mapped

view was mapped - launch a time-scheduled updateBlock

 sizeChanged: how

my size has changed - have to clear & redraw

 startClock

launch a time-scheduled updateBlock

 toggleStopWatch

self updateArmsFor:(self timeShown).

 initialize

initialize the view & precompute the tick-position-table

usage example(s):

initialize table of (normalized) x/y coordinates of ticks

 middleButtonMenu

(comment from inherited method)
return the menu associated with the middle mouse button.
Here, return a hooked on menu, but usually redefined to provide a widget-specific
menu.

 showSeconds: aBoolean

toggle (and possibly redraw) the show-seconds flag

 toggleSeconds

user wants to toggle the show-seconds flag

 copyTimeDuration

 destroy

the view was destroyed - remove time-scheduled updateBlock

 resetStopWatch

Demonstration:

    Clock start

Examples:

 |top clk|

 top := StandardSystemView new.
 top label:'ST/X clock'.
 top extent:200@200.

 clk := ClockView origin:0.0@0.0 corner:1.0@1.0 in:top.

 top open

 |top clk|

 top := StandardSystemView new.
 top label:'ST/X clock'.
 top extent:200@200.

 clk := ClockView origin:0.0@0.0 corner:1.0@1.0 in:top.
 clk beStopWatch.
 top open

 |top frame clk fileList|

 top := StandardSystemView new.
 top extent:200@200.

 frame := View origin:1.0@0.0 corner:1.0@50 in:top.
 frame leftInset:-50; rightInset:4; topInset:2; bottomInset:2.
 frame level:-1.

 clk := ClockView origin:0.0@0.0 corner:1.0@1.0 in:frame.
 clk showSeconds:false.

 fileList := ScrollableView for:FileSelectionList in:top.
 fileList origin:0@50 corner:1.0@1.0. 

 top open