{
* UStructs.pas
*
* Various structures. Some are extension of existing structures with added
* functionality.
*
* $Rev$
* $Date$
*
* ***** BEGIN LICENSE BLOCK *****
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
* the specific language governing rights and limitations under the License.
*
* The Original Code is UStructs.pas
*
* The Initial Developer of the Original Code is Peter Johnson
* (http://www.delphidabbler.com/).
*
* Portions created by the Initial Developer are Copyright (C) 2008-2010 Peter
* Johnson. All Rights Reserved.
*
* Contributor(s)
* NONE
*
* ***** END LICENSE BLOCK *****
}
unit UStructs;
interface
uses
// Delphi
Types;
type
{
TRectEx:
Encapsulates a rectangle. Assignment compatible with TRect. Has methods to
manipulate and cast rectangle.
}
TRectEx = packed record
Left, Top, // Coordinates of top left corner of rectangle
Right, Bottom: Longint; // Coordinates of bottom right corner of rectangle
constructor Create(ALeft, ATop, ARight, ABottom: Longint);
{Record constructor. Sets initial field values.
@param ALeft [in] Left position of rectangle.
@param ATop [in] Top position of rectangle.
@param ARight [in] Right position of rectangle.
@param ABottom [in] Bottom position of rectangle.
}
constructor CreateBounds(ALeft, ATop, AWidth, AHeight: Longint); overload;
{Record constructor. Creates rectangle from its bounds.
@param ALeft [in] Left position of rectangle.
@param ATop [in] Top position of rectangle.
@param AWidth [in] Width of rectangle.
@param AHeight [in] Height of rectangle.
}
constructor CreateBounds(ALeft, ATop: Longint; ASize: TSize); overload;
{Record constructor. Creates rectangle from its bounds.
@param ALeft [in] Left position of rectangle.
@param ATop [in] Top position of rectangle.
@param ASize [in] Size of rectangle.
}
class operator Implicit(ARect: TRect): TRectEx;
{Implicit cast of TRect to a TRectEx.
@param ARect [in] TRect to be cast.
@return TRectEx resulting from cast.
}
class operator Implicit(ARect: TRectEx): TRect;
{Implicit cast of TRectEx to a TRect.
@param ARect [in] TRectEx to be cast.
@return TRect resulting from cast.
}
class operator Equal(R1, R2: TRectEx): Boolean;
{Equality test for two TRectEx rectangles.
@param R1 [in] Left hand operand.
@param R2 [in] Right hand operand.
@return True if R1 is the same as R2, False if different.
}
class operator NotEqual(R1, R2: TRectEx): Boolean;
{Inequality test for two TRectEx rectangles.
@param R1 [in] Left hand operand.
@param R2 [in] Right hand operand.
@return True if R1 is different to R2, False if same.
}
function Width: Longint;
{Width of rectangle.
@return Required width.
}
function Height: Longint;
{Height of rectangle.
@return Required height.
}
procedure InflateBy(DeltaX, DeltaY: Longint);
{Inflates or deflates the rectangle.
@param DeltaX [in] Amount to inflate horizontally. Deflated if -ve.
@param DeltaY [in] Amount to inflate vertically. Deflated if -ve.
}
function Inflate(DeltaX, DeltaY: Longint): TRectEx;
{Returns a copy of rectangle, inflated or deflated.
@param DeltaX [in] Amount to inflate horizontally. Deflated if -ve.
@param DeltaY [in] Amount to inflate vertically. Deflated if -ve.
@return Inflated copy of rectangle.
}
procedure OffsetBy(AX, AY: Longint);
{Offsets rectangle in X and Y directions.
@param AX [in] Horizontal offset.
@param AY [in] Vertical offset.
}
function GetTopLeft: TPoint;
{Read accessor for TopLeft property.
@return Co-ordinates of top left of rectangle.
}
procedure SetTopLeft(const Value: TPoint);
{Write accessor for TopLeft property.
@param Value [in] Coordinates of top left.
}
function GetBottomRight: TPoint;
{Read accessor for BottomRight property.
@return Co-ordinates of bottom right of rectangle.
}
procedure SetBottomRight(const Value: TPoint);
{Write accessor for BottomRight property.
@param Value [in] Coordinates of bottom right.
}
function ContainsPoint(const Pt: TPoint): Boolean;
{Checks if a point is contained in the rectangle.
@param Pt [in] Point to be tested.
@return True if point is contained in the rectangle, False if not.
}
function IsEmpty: Boolean;
{Checks if a rectangle is empty. Empty is defined as Right <= Left or
Bottom <= Top.
return True if empty, False if not.
}
procedure MakeEmpty;
{Makes the rectangle empty.
}
property TopLeft: TPoint read GetTopLeft write SetTopLeft;
{Coordinates of top left corner of rectangle}
property BottomRight: TPoint read GetBottomRight write SetBottomRight;
{Coordinates of bottom right corner of rectangle}
end;
{
TRange:
Encapsulates a range of integers with a method to test wheter a value falls
within the range.
}
TRange = record
Min, Max: Integer; // Minimum and maximum bounds of range
constructor Create(AMin, AMax: Integer);
{Record constructor. Initialises range bounds.
@param AMin [in] Minimum value that falls in range.
@param AMax [in] Maximum value that falls in range.
}
function Contains(const Value: Integer): Boolean;
{Checks if a value is contained in range.
@param Value [in] Value to be tested.
@return True if Value is in range, False otherwise.
}
end;
{
TSelection:
Encapsulates a selection defined by its starting position and its length.
An empty selection has length 0.
}
TSelection = record
public
StartPos: Cardinal; // Start of selection
Length: Cardinal; // Length of selection
constructor Create(AStartPos: Cardinal; ALength: Cardinal = 0);
{Record constructor. Initialises start position and length.
@param AStartPos [in] Start of selection.
@param Length [in] Length of selection. Optional.
}
end;
implementation
uses
// Delphi
Math;
{ TRectEx }
function TRectEx.ContainsPoint(const Pt: TPoint): Boolean;
{Checks if a point is contained in the rectangle.
@param Pt [in] Point to be tested.
@return True if point is contained in the rectangle, False if not.
}
begin
Result := Types.PtInRect(Self, Pt);
end;
constructor TRectEx.Create(ALeft, ATop, ARight, ABottom: Integer);
{Record constructor. Sets initial field values.
@param ALeft [in] Left position of rectangle.
@param ATop [in] Top position of rectangle.
@param ARight [in] Right position of rectangle.
@param ABottom [in] Bottom position of rectangle.
}
begin
Left := ALeft;
Top := ATop;
Right := ARight;
Bottom := ABottom;
end;
constructor TRectEx.CreateBounds(ALeft, ATop, AWidth, AHeight: Integer);
{Record constructor. Creates rectangle from its bounds.
@param ALeft [in] Left position of rectangle.
@param ATop [in] Top position of rectangle.
@param AWidth [in] Width of rectangle.
@param AHeight [in] Height of rectangle.
}
begin
Create(ALeft, ATop, ALeft + AWidth, ATop + AHeight);
end;
constructor TRectEx.CreateBounds(ALeft, ATop: Integer; ASize: TSize);
{Record constructor. Creates rectangle from its bounds.
@param ALeft [in] Left position of rectangle.
@param ATop [in] Top position of rectangle.
@param ASize [in] Size of rectangle.
}
begin
CreateBounds(ALeft, ATop, ASize.cx, ASize.cy);
end;
class operator TRectEx.Equal(R1, R2: TRectEx): Boolean;
{Equality test for two TRectEx rectangles.
@param R1 [in] Left hand operand.
@param R2 [in] Right hand operand.
@return True if R1 is the same as R2, False if different.
}
begin
Result := (R1.Left = R2.Left) and (R1.Top = R2.Top)
and (R1.Right = R2.Right) and (R1.Bottom = R2.Bottom);
end;
function TRectEx.GetBottomRight: TPoint;
{Read accessor for BottomRight property.
@return Co-ordinates of bottom right of rectangle.
}
begin
Result.X := Right;
Result.Y := Bottom;
end;
function TRectEx.GetTopLeft: TPoint;
{Read accessor for TopLeft property.
@return Co-ordinates of top left of rectangle.
}
begin
Result.X := Left;
Result.Y := Top;
end;
function TRectEx.Height: Longint;
{Height of rectangle.
@return Required height.
}
begin
Result := Abs(Bottom - Top);
end;
class operator TRectEx.Implicit(ARect: TRectEx): TRect;
{Implicit cast of TRectEx to a TRect.
@param ARect [in] TRectEx to be cast.
@return TRect resulting from cast.
}
begin
Result.Left := ARect.Left;
Result.Top := ARect.Top;
Result.Right := ARect.Right;
Result.Bottom := ARect.Bottom;
end;
class operator TRectEx.Implicit(ARect: TRect): TRectEx;
{Implicit cast of TRect to a TRectEx.
@param ARect [in] TRect to be cast.
@return TRectEx resulting from cast.
}
begin
Result.Left := ARect.Left;
Result.Top := ARect.Top;
Result.Right := ARect.Right;
Result.Bottom := ARect.Bottom;
end;
function TRectEx.Inflate(DeltaX, DeltaY: Integer): TRectEx;
{Returns a copy of rectangle, inflated or deflated.
@param DeltaX [in] Amount to inflate horizontally. Deflated if -ve.
@param DeltaY [in] Amount to inflate vertically. Deflated if -ve.
@return Inflated copy of rectangle.
}
begin
Result := Self;
Result.InflateBy(DeltaX, DeltaY);
end;
procedure TRectEx.InflateBy(DeltaX, DeltaY: Integer);
{Inflates or deflates the rectangle.
@param DeltaX [in] Amount to inflate horizontally. Deflated if -ve.
@param DeltaY [in] Amount to inflate vertically. Deflated if -ve.
}
begin
Dec(Left, DeltaX);
Inc(Right, DeltaX);
Dec(Top, DeltaY);
Inc(Bottom, DeltaY);
end;
function TRectEx.IsEmpty: Boolean;
{Checks if a rectangle is empty. Empty is defined as Right <= Left or
Bottom <= Top.
return True if empty, False if not.
}
begin
Result := Types.IsRectEmpty(Self);
end;
procedure TRectEx.MakeEmpty;
{Makes the rectangle empty.
}
begin
Left := 0;
Top := 0;
Right := 0;
Bottom := 0;
end;
class operator TRectEx.NotEqual(R1, R2: TRectEx): Boolean;
{Inequality test for two TRectEx rectangles.
@param R1 [in] Left hand operand.
@param R2 [in] Right hand operand.
@return True if R1 is different to R2, False if same.
}
begin
Result := not (R1 = R2);
end;
procedure TRectEx.OffsetBy(AX, AY: Integer);
{Offsets rectangle in X and Y directions.
@param AX [in] Horizontal offset.
@param AY [in] Vertical offset.
}
begin
Inc(Left, AX);
Inc(Right, AX);
Inc(Top, AY);
Inc(Bottom, AY);
end;
procedure TRectEx.SetBottomRight(const Value: TPoint);
{Write accessor for BottomRight property.
@param Value [in] Coordinates of bottom right.
}
begin
Right := Value.X;
Bottom := Value.Y;
end;
procedure TRectEx.SetTopLeft(const Value: TPoint);
{Write accessor for TopLeft property.
@param Value [in] Coordinates of top left.
}
begin
Left := Value.X;
Top := Value.Y;
end;
function TRectEx.Width: Longint;
{Width of rectangle.
@return Required width.
}
begin
Result := Abs(Right - Left);
end;
{ TRange }
function TRange.Contains(const Value: Integer): Boolean;
{Checks if a value is contained in range.
@param Value [in] Value to be tested.
@return True if Value is in range, False otherwise.
}
begin
Result := Math.InRange(Value, Min, Max);
end;
constructor TRange.Create(AMin, AMax: Integer);
{Record constructor. Initialises range bounds.
@param AMin [in] Minimum value that falls in range.
@param AMax [in] Maximum value that falls in range.
}
begin
Min := AMin;
Max := AMax;
end;
{ TSelection }
constructor TSelection.Create(AStartPos, ALength: Cardinal);
{Record constructor. Initialises start position and length.
@param AStartPos [in] Start of selection.
@param Length [in] Length of selection. Optional.
}
begin
StartPos := AStartPos;
Length := ALength;
end;
end.
