| Description |
The TRect type is a record holding rectangle values as either 4 coordinates or 2 points.
This is a classic example of the use of the Case part of a record.
When creating from two points TopLeft and BottomRight, you can pass two TPoint values, or use the Point function to generate them.
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| Related commands |
| Bounds |
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Create a TRect value from top left and size values |
| Point |
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Generates a TPoint value from X and Y values |
| PointsEqual |
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Compares two TPoint values for equality |
| PtInRect |
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Tests to see if a point lies within a rectangle |
| Rect |
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Create a TRect value from 2 points or 4 coordinates |
| TPoint |
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Holds X and Y integer values |
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| Example code : Create one rectangle manually, another using Rect |
// Full Unit code.
// -----------------------------------------------------------
// You must store this code in a unit called Unit1 with a form
// called Form1 that has an OnCreate event called FormCreate.
unit Unit1;
interface
uses
Types, // Unit containing the TRect command
Classes,
Forms, Dialogs;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm} // Include form definitions
procedure TForm1.FormCreate(Sender: TObject);
var
rectangle1, rectangle2 : TRect;
begin
// Set up the first rectangle manually
rectangle1.Left := 0;
rectangle1.Top := 0;
rectangle1.Right := 40;
rectangle1.Bottom := 60;
// Set up the second rectangle using the Rect function
rectangle2 := Rect(Point(20, 40), Point(60, 80));
// Display the top left and bottom right coords of each rectangle
ShowMessageFmt('Rectangle 1 coords = %d,%d,%d,%d',
[rectangle1.Left,
rectangle1.Top,
rectangle1.Right,
rectangle1.Bottom]);
ShowMessageFmt('Rectangle 2 coords = %d,%d,%d,%d',
[rectangle2.Left,
rectangle2.Top,
rectangle2.Right,
rectangle2.Bottom]);
end;
end.
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| Hide full unit code |
Rectangle 1 coords = 0,0,40,60
Rectangle 2 coords = 20,40,60,80
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