{
* This Source Code Form is subject to the terms of the Mozilla Public License,
* v. 2.0. If a copy of the MPL was not distributed with this file, You can
* obtain one at http://mozilla.org/MPL/2.0/
*
* Copyright (C) 2005-2012, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Classes that encapsulate and provide information about "views" that are
* displayed in the user interface.
}
unit UView;
interface
uses
// Delphi
Generics.Collections,
// Project
DB.UCategory, DB.USnippet, DB.USnippetKind, UBaseObjects, UInitialLetter;
type
/// <summary>
/// Interface supported by object that can compare key values associated with
/// a view for equality.
/// </summary>
/// <remarks>
/// The values stored in this object must persist even if any object stored
/// in the related IView object has been destroyed.
/// </remarks>
IViewKey = interface(IInterface)
['{E6C39F3C-63E3-4A3E-A4E7-B176DA121D9E}']
/// <summary>Checks if two view keys are equal.</summary>
function IsEqual(const Key: IViewKey): Boolean;
end;
type
/// <summary>
/// Interface supported by all view objects.
/// </summary>
IView = interface(IInterface)
['{707ED3DC-1738-4B79-B1BE-1C554572097E}']
/// <summary>Checks if two viewsare equal, i.e. they have the same "type"
/// and any properties have the the same values.</summary>
function IsEqual(View: IView): Boolean;
/// <summary>Gets description of view.</summary>
function GetDescription: string;
/// <summary>Description of view.</summary>
property Description: string read GetDescription;
/// <summary>Gets object containing view's unique key.</summary>
/// <remarks>Encapsulates the data that uniquely identifies the view
/// without having have an instance of any object wrapped by the view.
/// </remarks>
function GetKey: IViewKey;
/// <summary>Checks if view is user-defined.</summary>
function IsUserDefined: Boolean;
/// <summary>Checks if view is a grouping.</summary>
/// <remarks>A grouping is a view that groups views together.
/// </remarks>
function IsGrouping: Boolean;
end;
type
/// <summary>
/// Interface supported by nul view.
/// </summary>
INulView = interface(IView)
['{18D06867-2E6D-4B62-A0A5-A269C91D18D6}']
end;
type
/// <summary>
/// Interface supported by new tab page view.
/// </summary>
INewTabView = interface(IView)
['{EF760E9C-2DEE-4CCA-AB85-E6C59AA100E7}']
end;
type
/// <summary>
/// Interface supported by start page view.
/// </summary>
IStartPageView = interface(IView)
['{9D2208C4-8FFC-4532-8C3F-07514EDFAB9D}']
end;
type
/// <summary>
/// Interface supported by view that provides info about a database update.
/// </summary>
IDBUpdateInfoView = interface(IView)
['{0E5220F3-33EE-4832-9533-B97B3F3E519B}']
end;
type
/// <summary>
/// Interface supported by snippet views.
/// </summary>
ISnippetView = interface(IView)
['{E0BD3AB7-2CB8-4B07-84D9-D7625DD020B0}']
/// <summary>Gets reference to snippet associated with view.</summary>
function GetSnippet: TSnippet;
/// <summary>Snippet associated with view.</summary>
property Snippet: TSnippet read GetSnippet;
end;
type
/// <summary>
/// Interface supported by category views.
/// </summary>
ICategoryView = interface(IView)
['{C8BB04FD-B0B7-42F9-84AA-2F7FDD3A6FE8}']
/// <summary>Gets reference to category associated with view.</summary>
function GetCategory: TCategory;
/// <summary>Category associated with view.</summary>
property Category: TCategory read GetCategory;
end;
type
/// <summary>
/// Interface supported by snippet kind views.
/// </summary>
ISnippetKindView = interface(IView)
['{FE074E72-857F-4D43-A17D-A951830B78E4}']
/// <summary>Gets info about snippet kind associated with view.</summary>
function GetKindInfo: TSnippetKindInfo;
/// <summary>Info about snippet kind associated with view.</summary>
property KindInfo: TSnippetKindInfo read GetKindInfo;
end;
type
/// <summary>
/// Interface supported by initial letter views.
/// </summary>
IInitialLetterView = interface(IView)
['{E589E3E9-7178-4FF8-BDEF-D6F7DC9FEB85}']
/// <summary>Gets info about initial letter associated with view.</summary>
function GetInitialLetter: TInitialLetter;
/// <summary>Info about initial letter associated with view.</summary>
property InitialLetter: TInitialLetter read GetInitialLetter;
end;
type
/// <summary>
/// List of views.
/// </summary>
TViewList = class sealed(TList<IView>);
type
/// <summary>
/// Static factory class used to create view instances of different types.
/// </summary>
TViewFactory = class sealed(TNoConstructObject)
public
/// <summary>Creates a copy of the given view. Copy has same type and
/// properties.</summary>
class function Clone(View: IView): IView;
/// <summary>Creates a nul view instance.</summary>
class function CreateNulView: IView;
/// <summary>Creates a new tab view instance.</summary>
class function CreateNewTabView: IView;
/// <summary>Creates a start page view instance.</summary>
class function CreateStartPageView: IView;
/// <summary>Creates a database update information view instance.
/// </summary>
class function CreateDBUpdateInfoView: IView;
/// <summary>Creates a snippet view instance associated with a given
/// snippet.</summary>
class function CreateSnippetView(const Snippet: TSnippet): IView;
/// <summary>Creates a category view instance associated with a given
/// category.</summary>
class function CreateCategoryView(const Category: TCategory): IView;
/// <summary>Creates a snippet kind view instance associated with a given
/// snippet kind.</summary>
class function CreateSnippetKindView(const KindInfo: TSnippetKindInfo):
IView;
/// <summary>Creates an initial letter view instance associated with a
/// given letter.</summary>
class function CreateInitialLetterView(const Letter: TInitialLetter): IView;
/// <summary>Creates a view of given database object. View type depends on
/// the object's type.</summary>
/// <remarks>Database object type must be valid, i.e. either TSnippet or
/// TCategory, or nil.</remarks>
class function CreateDBItemView(const DBObj: TObject): IView;
end;
implementation
uses
// Delphi
SysUtils,
// Project
DB.UMain, UExceptions, USnippetIDs, UStrUtils;
type
/// <summary>
/// Base class for views that contain no other object references and are used
/// simply for display in the details pane.
/// </summary>
TSimpleView = class abstract(TInterfacedObject)
strict private
type
/// <summary>Implementation of IViewKey for descendants.</summary>
TKey = class(TInterfacedObject, IViewKey)
strict private
/// <summary>Class of object that owns this key.</summary>
fOwnerClass: TClass;
public
/// <summary>Constructs object with given owner class.</summary>
constructor Create(OwnerClass: TClass);
/// <summary>Checks if this key is equal to one passed as a parameter.
/// </summary>
/// <remarks>Method of IViewKey.</remarks>
function IsEqual(const Key: IViewKey): Boolean;
end;
public
/// <summary>Checks if this view is equal to the one passed as a parameter.
/// </summary>
/// <remarks>Method of IView.</remarks>
function IsEqual(View: IView): Boolean;
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string; virtual; abstract;
/// <summary>Gets object containing view's unique key.</summary>
/// <remarks>Method of IView.</remarks>
function GetKey: IViewKey;
/// <summary>Checks if view is user-defined.</summary>
/// <remarks>Method of IView.</remarks>
function IsUserDefined: Boolean;
/// <summary>Checks if view is a grouping.</summary>
/// <remarks>Method of IView.</remarks>
function IsGrouping: Boolean;
end;
type
/// <summary>Nul view.</summary>
TNulView = class sealed(TSimpleView,
IView, INulView
)
public
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string; override;
end;
type
/// <summary>View associated with blank new tab pages.</summary>
TNewTabView = class sealed(TSimpleView,
IView, INewTabView
)
public
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string; override;
end;
type
/// <summary>View associated with start page.</summary>
TStartPageView = class sealed(TSimpleView,
IView, IStartPageView
)
public
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string; override;
end;
type
/// <summary>View associated with information about a database update.
/// </summary>
TDBUpdateInfoView = class sealed(TSimpleView,
IView, IDBUpdateInfoView
)
public
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string; override;
end;
type
/// <summary>View associated with a snippet.</summary>
TSnippetView = class sealed(TInterfacedObject,
IView, ISnippetView
)
strict private
var
/// <summary>ID of snippet associated with view.</summary>
fSnippetID: TSnippetID;
type
/// <summary>Implementation of IViewKey for snippet view.</summary>
TKey = class(TInterfacedObject, IViewKey)
strict private
var
/// <summary>Snippet id used as key.</summary>
fID: TSnippetID;
public
/// <summary>Constructs object with given snippet id as key.</summary>
constructor Create(const ID: TSnippetID);
/// <summary>Checks if this key is equal to one passed as a parameter.
/// </summary>
/// <remarks>Method of IViewKey.</remarks>
function IsEqual(const Key: IViewKey): Boolean;
end;
public
/// <summary>Constructs view for a specified snippet.</summary>
constructor Create(const Snippet: TSnippet);
/// <summary>Checks if this view is equal to the one passed as a parameter.
/// </summary>
/// <remarks>Method of IView.</remarks>
function IsEqual(View: IView): Boolean;
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string;
/// <summary>Gets object containing view's unique key.</summary>
/// <remarks>Method of IView.</remarks>
function GetKey: IViewKey;
/// <summary>Checks if view is user-defined.</summary>
function IsUserDefined: Boolean;
/// <summary>Checks if view is a grouping.</summary>
/// <remarks>Method of IView.</remarks>
function IsGrouping: Boolean;
/// <summary>Gets reference to snippet associated with view.</summary>
/// <remarks>Method of ISnippetView.</remarks>
function GetSnippet: TSnippet;
end;
type
/// <summary>View associated with a category.</summary>
TCategoryView = class sealed(TInterfacedObject,
IView, ICategoryView
)
strict private
var
/// <summary>ID of category associated with view.</summary>
fCategoryID: string;
type
/// <summary>Implementation of IViewKey for category view.</summary>
TKey = class(TInterfacedObject, IViewKey)
strict private
var
/// <summary>Category id used as key.</summary>
fID: string;
public
/// <summary>Constructs object with given category id as key.</summary>
constructor Create(const ID: string);
/// <summary>Checks if this key is equal to one passed as a parameter.
/// </summary>
/// <remarks>Method of IViewKey.</remarks>
function IsEqual(const Key: IViewKey): Boolean;
end;
public
/// <summary>Constructs view for a specified category.</summary>
constructor Create(const Category: TCategory);
/// <summary>Checks if this view is equal to the one passed as a parameter.
/// </summary>
/// <remarks>Method of IView.</remarks>
function IsEqual(View: IView): Boolean;
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string;
/// <summary>Gets object containing view's unique key.</summary>
/// <remarks>Method of IView.</remarks>
function GetKey: IViewKey;
/// <summary>Checks if view is user-defined.</summary>
/// <remarks>Method of IView.</remarks>
function IsUserDefined: Boolean;
/// <summary>Checks if view is a grouping.</summary>
/// <remarks>Method of IView.</remarks>
function IsGrouping: Boolean;
/// <summary>Gets reference to category associated with view.</summary>
/// <remarks>Method of ICategoryView.</remarks>
function GetCategory: TCategory;
end;
type
/// <summary>View associated with a snippet kind grouping.</summary>
TSnippetKindView = class sealed(TInterfacedObject,
IView, ISnippetKindView
)
strict private
var
/// <summary>Snippet kind associated with view.</summary>
fKindInfo: TSnippetKindInfo;
type
/// <summary>Implementation of IViewKey for snippet kind view.
/// </summary>
TKey = class(TInterfacedObject, IViewKey)
strict private
var
/// <summary>Snippet kind used as key.</summary>
fID: TSnippetKind;
public
/// <summary>Constructs object with given snippet kind as key.
/// </summary>
constructor Create(const ID: TSnippetKind);
/// <summary>Checks if this key is equal to one passed as a parameter.
/// </summary>
/// <remarks>Method of IViewKey.</remarks>
function IsEqual(const Key: IViewKey): Boolean;
end;
public
/// <summary>Constructs view for a specified snippet kind.</summary>
constructor Create(const KindInfo: TSnippetKindInfo);
/// <summary>Checks if this view is equal to the one passed as a parameter.
/// </summary>
/// <remarks>Method of IView.</remarks>
function IsEqual(View: IView): Boolean;
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string;
/// <summary>Gets object containing view's unique key.</summary>
/// <remarks>Method of IView.</remarks>
function GetKey: IViewKey;
/// <summary>Checks if view is user-defined.</summary>
/// <remarks>Method of IView.</remarks>
function IsUserDefined: Boolean;
/// <summary>Checks if view is a grouping.</summary>
/// <remarks>Method of IView.</remarks>
function IsGrouping: Boolean;
/// <summary>Gets info about snippet kind associated with view.</summary>
/// <remarks>Method of ISnippetKindView.</remarks>
function GetKindInfo: TSnippetKindInfo;
end;
type
/// <summary>View associated with an initial letter grouping.</summary>
TInitialLetterView = class sealed(TInterfacedObject,
IView, IInitialLetterView
)
strict private
var
/// <summary>Initial letter associated with view.</summary>
fInitialLetter: TInitialLetter;
type
/// <summary>Implementation of IViewKey for initial letter view.
/// </summary>
TKey = class(TInterfacedObject, IViewKey)
strict private
var
/// <summary>Initial letter used as key.</summary>
fID: TInitialLetter;
public
/// <summary>Constructs object with given initial letter as key.
/// </summary>
constructor Create(const ID: TInitialLetter);
/// <summary>Checks if this key is equal to one passed as a parameter.
/// </summary>
/// <remarks>Method of IViewKey.</remarks>
function IsEqual(const Key: IViewKey): Boolean;
end;
public
/// <summary>Constructs view for a specified initial letter.</summary>
constructor Create(const Letter: TInitialLetter);
/// <summary>Checks if this view is equal to the one passed as a parameter.
/// </summary>
/// <remarks>Method of IView.</remarks>
function IsEqual(View: IView): Boolean;
/// <summary>Gets description of view.</summary>
/// <remarks>Method of IView.</remarks>
function GetDescription: string;
/// <summary>Gets object containing view's unique key.</summary>
/// <remarks>Method of IView.</remarks>
function GetKey: IViewKey;
/// <summary>Checks if view is user-defined.</summary>
/// <remarks>Method of IView.</remarks>
function IsUserDefined: Boolean;
/// <summary>Checks if view is a grouping.</summary>
/// <remarks>Method of IView.</remarks>
function IsGrouping: Boolean;
/// <summary>Gets unfo about initial letter associated with view.</summary>
/// <remarks>Method of IInitialLetterView.</remarks>
function GetInitialLetter: TInitialLetter;
end;
{ TSimpleView }
function TSimpleView.GetKey: IViewKey;
begin
Result := TKey.Create(Self.ClassType);
end;
function TSimpleView.IsEqual(View: IView): Boolean;
begin
Result := View.GetKey.IsEqual(Self.GetKey);
end;
function TSimpleView.IsGrouping: Boolean;
begin
Result := False;
end;
function TSimpleView.IsUserDefined: Boolean;
begin
Result := False;
end;
{ TSimpleView.TKey }
constructor TSimpleView.TKey.Create(OwnerClass: TClass);
begin
inherited Create;
fOwnerClass := OwnerClass;
end;
function TSimpleView.TKey.IsEqual(const Key: IViewKey): Boolean;
begin
Result := (Key is TKey) and ((Key as TKey).fOwnerClass = Self.fOwnerClass);
end;
{ TNulView }
function TNulView.GetDescription: string;
begin
Result := '';
end;
{ TNewTabView }
function TNewTabView.GetDescription: string;
resourcestring
sDescription = 'Empty tab';
begin
Result := sDescription;
end;
{ TStartPageView }
function TStartPageView.GetDescription: string;
resourcestring
sDesc = 'Welcome';
begin
Result := sDesc;
end;
{ TDBUpdateInfoView }
function TDBUpdateInfoView.GetDescription: string;
resourcestring
sDesc = 'Database Updated';
begin
Result := sDesc;
end;
{ TSnippetView }
constructor TSnippetView.Create(const Snippet: TSnippet);
begin
inherited Create;
fSnippetID := Snippet.ID;
end;
function TSnippetView.GetDescription: string;
begin
Result := GetSnippet.DisplayName;
end;
function TSnippetView.GetKey: IViewKey;
begin
Result := TKey.Create(fSnippetID);
end;
function TSnippetView.GetSnippet: TSnippet;
begin
Result := Database.Snippets.Find(fSnippetID);
Assert(Assigned(Result), ClassName + '.GetSnippet: Snippet not found');
end;
function TSnippetView.IsEqual(View: IView): Boolean;
var
SnippetView: ISnippetView;
begin
if not Supports(View, ISnippetView, SnippetView) then
Exit(False);
// don't compare snippet IDs directly in case snippet equality test changes
Result := GetSnippet.IsEqual(SnippetView.Snippet);
end;
function TSnippetView.IsGrouping: Boolean;
begin
Result := False;
end;
function TSnippetView.IsUserDefined: Boolean;
begin
Result := GetSnippet.UserDefined;
end;
{ TSnippetView.TKey }
constructor TSnippetView.TKey.Create(const ID: TSnippetID);
begin
inherited Create;
fID := ID;
end;
function TSnippetView.TKey.IsEqual(const Key: IViewKey): Boolean;
begin
if not (Key is TSnippetView.TKey) then
Exit(False);
Result := (Key as TSnippetView.TKey).fID = fID;
end;
{ TCategoryView }
constructor TCategoryView.Create(const Category: TCategory);
begin
inherited Create;
fCategoryID := Category.ID;
end;
function TCategoryView.GetCategory: TCategory;
begin
Result := Database.Categories.Find(fCategoryID);
Assert(Assigned(Result), ClassName + '.GetCategory: Category not found');
end;
function TCategoryView.GetDescription: string;
begin
Result := GetCategory.Description;
end;
function TCategoryView.GetKey: IViewKey;
begin
Result := TKey.Create(GetCategory.ID);
end;
function TCategoryView.IsEqual(View: IView): Boolean;
var
CatView: ICategoryView;
begin
if not Supports(View, ICategoryView, CatView) then
Exit(False);
// don't compare category IDs directly in case equality test changes
Result := GetCategory.IsEqual(CatView.Category);
end;
function TCategoryView.IsGrouping: Boolean;
begin
Result := True;
end;
function TCategoryView.IsUserDefined: Boolean;
begin
Result := GetCategory.UserDefined;
end;
{ TCategoryView.TKey }
constructor TCategoryView.TKey.Create(const ID: string);
begin
inherited Create;
fID := ID;
end;
function TCategoryView.TKey.IsEqual(const Key: IViewKey): Boolean;
begin
if not (Key is TKey) then
Exit(False);
Result := StrSameText((Key as TKey).fID, fID);
end;
{ TSnippetKindView }
constructor TSnippetKindView.Create(const KindInfo: TSnippetKindInfo);
begin
inherited Create;
fKindInfo := KindInfo;
end;
function TSnippetKindView.GetDescription: string;
begin
Result := GetKindInfo.DisplayName;
end;
function TSnippetKindView.GetKey: IViewKey;
begin
Result := TKey.Create(GetKindInfo.Kind);
end;
function TSnippetKindView.GetKindInfo: TSnippetKindInfo;
begin
Result := fKindInfo;
end;
function TSnippetKindView.IsEqual(View: IView): Boolean;
var
SnipKindView: ISnippetKindView;
begin
if not Supports(View, ISnippetKindView, SnipKindView) then
Exit(False);
Result := GetKindInfo.Kind = SnipKindView.KindInfo.Kind;
end;
function TSnippetKindView.IsGrouping: Boolean;
begin
Result := True;
end;
function TSnippetKindView.IsUserDefined: Boolean;
begin
Result := False;
end;
{ TSnippetKindView.TKey }
constructor TSnippetKindView.TKey.Create(const ID: TSnippetKind);
begin
inherited Create;
fID := ID;
end;
function TSnippetKindView.TKey.IsEqual(const Key: IViewKey): Boolean;
begin
if not (Key is TKey) then
Exit(False);
Result := (Key as TKey).fID = fID;
end;
{ TInitialLetterView }
constructor TInitialLetterView.Create(const Letter: TInitialLetter);
begin
inherited Create;
fInitialLetter := Letter;
end;
function TInitialLetterView.GetDescription: string;
begin
Result := GetInitialLetter.Letter;
end;
function TInitialLetterView.GetInitialLetter: TInitialLetter;
begin
Result := fInitialLetter;
end;
function TInitialLetterView.GetKey: IViewKey;
begin
Result := TKey.Create(GetInitialLetter);
end;
function TInitialLetterView.IsEqual(View: IView): Boolean;
var
LetterView: IInitialLetterView;
begin
if not Supports(View, IInitialLetterView, LetterView) then
Exit(False);
Result := GetInitialLetter = LetterView.InitialLetter;
end;
function TInitialLetterView.IsGrouping: Boolean;
begin
Result := True;
end;
function TInitialLetterView.IsUserDefined: Boolean;
begin
Result := False;
end;
{ TInitialLetterView.TKey }
constructor TInitialLetterView.TKey.Create(const ID: TInitialLetter);
begin
inherited Create;
fID := ID;
end;
function TInitialLetterView.TKey.IsEqual(const Key: IViewKey): Boolean;
begin
if not (Key is TKey) then
Exit(False);
Result := (Key as TKey).fID = fID;
end;
{ TViewFactory }
class function TViewFactory.Clone(View: IView): IView;
begin
if not Assigned(View) or Supports(View, INulView) then
Result := CreateNulView // also created if View = nil
else if Supports(View, IStartPageView) then
Result := CreateStartPageView
else if Supports(View, ISnippetView) then
Result := CreateSnippetView((View as ISnippetView).Snippet)
else if Supports(View, ICategoryView) then
Result := CreateCategoryView((View as ICategoryView).Category)
else if Supports(View, ISnippetKindView) then
Result := CreateSnippetKindView((View as ISnippetKindView).KindInfo)
else if Supports(View, IInitialLetterView) then
Result := CreateInitialLetterView(
(View as IInitialLetterView).InitialLetter
)
else if Supports(View, INewTabView) then
Result := CreateNewTabView
else if Supports(View, IDBUpdateInfoView) then
Result := CreateDBUpdateInfoView
else
raise EBug.CreateFmt(
'%s.CreateCopy: View does not support a valid interface', [ClassName]
);
end;
class function TViewFactory.CreateCategoryView(const Category: TCategory):
IView;
begin
Result := TCategoryView.Create(Category);
end;
class function TViewFactory.CreateDBItemView(const DBObj: TObject): IView;
begin
Result := nil;
if not Assigned(DBObj) then
Result := TViewFactory.CreateNulView
else if DBObj is TSnippet then
Result := TViewFactory.CreateSnippetView(DBObj as TSnippet)
else if DBObj is TCategory then
Result := TViewFactory.CreateCategoryView(DBObj as TCategory);
Assert(Assigned(Result),
ClassName + '.CreateDBItemView: DBObj is not valid type');
end;
class function TViewFactory.CreateDBUpdateInfoView: IView;
begin
Result := TDBUpdateInfoView.Create;
end;
class function TViewFactory.CreateInitialLetterView(
const Letter: TInitialLetter): IView;
begin
Result := TInitialLetterView.Create(Letter);
end;
class function TViewFactory.CreateNewTabView: IView;
begin
Result := TNewTabView.Create;
end;
class function TViewFactory.CreateNulView: IView;
begin
Result := TNulView.Create;
end;
class function TViewFactory.CreateSnippetKindView(
const KindInfo: TSnippetKindInfo): IView;
begin
Result := TSnippetKindView.Create(KindInfo);
end;
class function TViewFactory.CreateSnippetView(
const Snippet: TSnippet): IView;
begin
Result := TSnippetView.Create(Snippet);
end;
class function TViewFactory.CreateStartPageView: IView;
begin
Result := TStartPageView.Create;
end;
end.
