{
* UCSSBuilder.pas
*
* Classes that help create and manage cascading style sheet code.
*
* $Rev$
* $Date$
*
* ***** 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 UCSSBuilder.pas
*
* The Initial Developer of the Original Code is Peter Johnson
* (http://www.delphidabbler.com/).
*
* Portions created by the Initial Developer are Copyright (C) 2005-2010 Peter
* Johnson. All Rights Reserved.
*
* Contributor(s)
* NONE
*
* ***** END LICENSE BLOCK *****
}
unit UCSSBuilder;
interface
uses
// Delphi
Generics.Collections,
// Project
UIStringList;
type
{
TCSSSelector:
Class that encapsulates a CSS selector and outputs its CSS code.
}
TCSSSelector = class(TObject)
strict private
var
fProperties: IStringList; // List of properties for this selector
fSelector: string; // Name of selector
public
constructor Create(const Selector: string);
{Constructor. Creates a CSS selector object with given name.
@param Selector [in] Name of selector.
}
function AsString: string;
{Generates the CSS code representing the selector.
@return Required CSS code.
}
function IsEmpty: Boolean;
{Checks whether the selector is empty, i.e. contains no code.
@return True if selector is empty and false if not.
}
procedure AddProperty(const CSSProp: string);
{Adds a new CSS property to the selector.
@param CSSProp [in] CSS property to be added.
}
property Selector: string read fSelector;
{Name of selector}
end;
{
TCSSBuilder:
Class that creates a CSS style sheet and outputs its CSS code.
}
TCSSBuilder = class(TObject)
strict private
type
// Class that maps CSS selector names to selector objects
TCSSSelectorMap = TObjectDictionary<string,TCSSSelector>;
var
fSelectors: TCSSSelectorMap; // Maps selector names to selector objects
function GetSelector(const Selector: string): TCSSSelector;
{Read access method for Selectors property. Returns selector object with
given name.
@param Selector [in] Name of required selector.
@return Selector object with given name or nil if not found.
}
public
constructor Create;
{Constructor. Sets up object.
}
destructor Destroy; override;
{Destructor. Tears down object.
}
function AddSelector(const Selector: string): TCSSSelector;
{Adds a new empty selector with given name to style sheet.
@param Selector [in] Name of new selector.
@return New empty selector object.
}
procedure Clear;
{Clears all selectors from style sheet and frees selector objects.
}
function AsString: string;
{Generates CSS code representing the style sheet.
@return Required CSS code.
}
property Selectors[const Selector: string]: TCSSSelector
read GetSelector;
{Array of CSS selectors in style sheet, indexed by selector name}
end;
implementation
uses
// Project
UComparers, UConsts;
{ TCSSSelector }
procedure TCSSSelector.AddProperty(const CSSProp: string);
{Adds a new CSS property to the selector.
@param CSSProp [in] CSS property to be added.
}
begin
fProperties.Add(CSSProp);
end;
function TCSSSelector.AsString: string;
{Generates the CSS code representing the selector.
@return Required CSS code.
}
var
Lines: IStringList; // lines of CSS
begin
Lines := TIStringList.Create;
// Compose CSS selector statement
Lines.Add(Selector + ' {');
if fProperties.Count > 0 then
Lines.Add(fProperties);
Lines.Add('}');
// Write CSS in string
Result := Lines.GetText(EOL, False) + EOL;
end;
constructor TCSSSelector.Create(const Selector: string);
{Constructor. Creates a CSS selector object with given name.
@param Selector [in] Name of selector.
}
begin
Assert(Selector <> '', ClassName + '.Create: selector is empty string');
inherited Create;
fSelector := Selector;
fProperties := TIStringList.Create;
end;
function TCSSSelector.IsEmpty: Boolean;
{Checks whether the selector is empty, i.e. contains no code.
@return True if selector is empty and false if not.
}
begin
// Selector is empty if background colour not set, there is no font,
// margin is not defined and there is no extra CSS
Result := fProperties.Count = 0;
end;
{ TCSSBuilder }
function TCSSBuilder.AddSelector(const Selector: string): TCSSSelector;
{Adds a new empty selector with given name to style sheet.
@param Selector [in] Name of new selector.
@return New empty selector object.
}
begin
Result := TCSSSelector.Create(Selector);
fSelectors.Add(Selector, Result);
end;
function TCSSBuilder.AsString: string;
{Generates CSS code representing the style sheet.
@return Required CSS code.
}
var
Selector: TCSSSelector; // reference to each selector in map
begin
Result := '';
for Selector in fSelectors.Values do
if not Selector.IsEmpty then
Result := Result + Selector.AsString;
end;
procedure TCSSBuilder.Clear;
{Clears all selectors from style sheet and frees selector objects.
}
begin
fSelectors.Clear; // frees selector objects in .Values[]
end;
constructor TCSSBuilder.Create;
{Constructor. Sets up object.
}
begin
inherited;
// fSelectors treats selector names are not case sensitive
// fSelectors owns value objects and frees them when they are removed from map
fSelectors := TCSSSelectorMap.Create(
[doOwnsValues], TSameTextEqualityComparer.Create
);
end;
destructor TCSSBuilder.Destroy;
{Destructor. Tears down object.
}
begin
fSelectors.Free; // frees selector objects in fSelectors.Values[]
inherited;
end;
function TCSSBuilder.GetSelector(const Selector: string): TCSSSelector;
{Read access method for Selectors property. Returns selector object with given
name.
@param Selector [in] Name of required selector.
@return Selector object with given name or nil if not found.
}
begin
if fSelectors.ContainsKey(Selector) then
Result := fSelectors[Selector]
else
Result := nil;
end;
end.
