{
* 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) 2013, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Implements a dialogue box that displays and manages the user's favourite
* snippets.
}
unit FmFavouritesDlg;
interface
uses
// Delphi
Classes, ActnList, StdCtrls, Controls, ExtCtrls, Forms, ComCtrls, Types,
Generics.Collections {must be listed after Classes},
// 3rd party
LVEx,
// Project
FmGenericNonModalDlg, Favourites.UFavourites, IntfNotifier, USnippetIDs,
UWindowSettings;
type
/// <summary>Implements a non-modal dialogue box that displays and manages
/// the user's favourite snippets.</summary>
/// <remarks>By default the dialogue box fades to semi-transparency when it
/// is not active and returns to full opacity when activated.</remarks>
TFavouritesDlg = class(TGenericNonModalDlg)
actDelete: TAction;
actDeleteAll: TAction;
actDisplay: TAction;
alDlg: TActionList;
btnDelete: TButton;
btnDeleteAll: TButton;
btnDisplay: TButton;
chkNewTab: TCheckBox;
lblTransparency: TLabel;
tbTransparency: TTrackBar;
/// <summary>Clears all favourites.</summary>
/// <remarks>Prompts user for permission before proceeding.</remarks>
procedure actDeleteAllExecute(Sender: TObject);
/// <summary>Disables DeleteAll action iff there are no favourites.
/// </summary>
procedure actDeleteAllUpdate(Sender: TObject);
/// <summary>Removes favourite selected in list view from list.</summary>
procedure actDeleteExecute(Sender: TObject);
/// <summary>Enables Delete action iff a favourite is selected in list
/// view.</summary>
procedure actDeleteUpdate(Sender: TObject);
/// <summary>Displays favourite selected in list view.</summary>
procedure actDisplayExecute(Sender: TObject);
/// <summary>Enables Display action iff a favourite is selected in list
/// view.</summary>
procedure actDisplayUpdate(Sender: TObject);
/// <summary>Fades form to full opacity when dialogue box is activated.
/// </summary>
procedure FormActivate(Sender: TObject);
/// <summary>Causes form's object instance to be automatically freed when
/// closed.</summary>
procedure FormClose(Sender: TObject; var Action: TCloseAction);
/// <summary>Sets default property values when form is created.</summary>
procedure FormCreate(Sender: TObject);
/// <summary>Fades form to specified transparency when dialogue box is
/// de-activated.</summary>
procedure FormDeactivate(Sender: TObject);
/// <summary>Saves form's window state before form is destroyed.</summary>
procedure FormDestroy(Sender: TObject);
/// <summary>Adjusts form transparency according to new trackbar position
/// whenever it changes.</summary>
procedure tbTransparencyChange(Sender: TObject);
/// <summary>Records that a key has been pressed over the transparency
/// trackbar and fades the form down to the transparency specified by the
/// trackbar.</summary>
procedure tbTransparencyKeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
/// <summary>Records that the currently depressed key has been released
/// over the trackbar and fades the form back up to full opacity.</summary>
procedure tbTransparencyKeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
strict private
type
/// <summary>Reads and stores persistent options in settings.</summary>
TPersistentOptions = class(TObject)
strict private
var
/// <summary>Value of DisplayInNewTabs property.</summary>
fDisplayInNewTabs: Boolean;
/// <summary>Value of InactiveAlphaBlendValue property.</summary>
fInactiveAlphaBlendValue: Byte;
const
/// <summary>Name of settings key where DisplayInNewTabs property is
/// stored.</summary>
DisplayInNewTabsKey = 'DisplayInNewTabs';
/// <summary>Name of settings key where InactiveAlphaBlendValue
/// property is stored.</summary>
InactiveAlphaBlendValueKey = 'InactiveAlphaBlendValue';
public
/// <summary>Constructs object and reads options from settings.
/// </summary>
constructor Create;
/// <summary>Writes options to settings then destroys object.</summary>
destructor Destroy; override;
/// <summary>Specifies whether or not selected favourites are to be
/// displayed in new tabs in main window's detail pane.</summary>
property DisplayInNewTabs: Boolean
read fDisplayInNewTabs write fDisplayInNewTabs;
/// <summary>Stores alpha blend value that determines transparency of
/// deactivated form.</summary>
property InactiveAlphaBlendValue: Byte
read fInactiveAlphaBlendValue write fInactiveAlphaBlendValue;
end;
strict private
var
/// <summary>Custom list view control used to display favourites.
/// </summary>
fLVFavs: TListViewEx;
/// <summary>Object encapsulating favourites.</summary>
fFavourites: TFavourites;
/// <summary>Notifier object used to request display of snippets in main
/// form.</summary>
fNotifier: INotifier;
/// <summary>Form's persistent options.</summary>
fOptions: TPersistentOptions;
/// <summary>Object used to read / write window position in settings.
/// </summary>
fWindowSettings: TDlgWindowSettings;
/// <summary>Flag indicating if a key is currently pressed when the
/// transparency trackbar has keyboard focus.</summary>
fTrackBarKeyDown: Boolean;
/// <summary>Flag indicating if the mouse is currently pressed over the
/// transparency trackbar.</summary>
fTrackBarMouseDown: Boolean;
class var
/// <summary>Reference to dialogue box form instance.</summary>
/// <remarks>Set to nil if there is no instance of the form.</remarks>
fInstance: TFavouritesDlg;
strict private
/// <summary>Specifies class to be used to create favourites list view
/// items.</summary>
/// <param name="Sender">TCustomListView [in] List view control for which
/// list item class is required.</param>
/// <param name="ItemClass">TListItemClass [in/out] Set to required class:
/// TFavouriteListItem in all cases.</param>
procedure LVFavouriteCreateItemClass(Sender: TCustomListView;
var ItemClass: TListItemClass);
/// <summary>Compares two list items, Item1 and Item2 and records the
/// result of the comparison in the Compare parameter.</summary>
/// <remarks>Comparison depends on which column of data is being sorted.
/// </remarks>
procedure LVFavouritesCompare(Sender: TObject; Item1, Item2: TListItem;
Data: Integer; var Compare: Integer);
/// <summary>Handles double clicks on list view items by causing the
/// associated favourite's snippet to be displayed.</summary>
procedure LVDoubleClick(Sender: TObject);
/// <summary>Overrides default drawing of given list view item caption by
/// ensuring the associated favourite's snippet display name is rendered in
/// correct colour.</summary>
/// <remarks>Colour used depends on whether snippet is user defined.
/// </remarks>
procedure LVCustomDrawItem(Sender: TCustomListView; Item: TListItem;
State: TCustomDrawState; var DefaultDraw: Boolean);
/// <summary>Ensures that given list view sub item is drawn in correct
/// colour.</summary>
/// <remarks>Colour is reverted to window text instead of colour set in
/// LVCustomDrawItem method.</remarks>
procedure LVCustomDrawSubItem(Sender: TCustomListView; Item: TListItem;
SubItem: Integer; State: TCustomDrawState; var DefaultDraw: Boolean);
/// <summary>Creates and initialises properties of custom list view control
/// that is used to display favourites.</summary>
procedure CreateLV;
/// <summary>Displays all favourites in favourites list view.</summary>
procedure PopulateLV;
/// <summary>Resorts favourites list view according to current sort column.
/// </summary>
procedure ReSortLV;
/// <summary>Adds given favourite to favourites list view.</summary>
procedure AddLVItem(const Favourite: TFavourite);
/// <summary>Removes given favourite from favourites list view.</summary>
/// <remarks>Does nothing if favourite is not in list view.</remarks>
procedure RemoveLVItem(const Favourite: TFavourite);
/// <summary>Listener method that receives and acts on change events
/// triggered by favourites object.</summary>
/// <param name="Sender">TObject [in] Reference to favourites object that
/// triggered event.</param>
/// <param name="EvtInfo">IInterface [in] Reference to object that carries
/// information about the event.</param>
/// <remarks>EvtInfo must support IFavouritesChangeEventInfo.</remarks>
procedure FavouritesListener(Sender: TObject; const EvtInfo: IInterface);
/// <summary>Changes the transparency of the form from its current level to
/// the given new transparency level.</summary>
/// <remarks>The change in transparency is performed in small steps to make
/// it appear animated.</remarks>
procedure FadeTo(const NewTransparency: Byte);
/// <summary>Fades the form in from its current transparent state to full
/// opacity.</summary>
procedure FadeIn;
/// <summary>Fades the form from its current transparency to the level
/// indicated by the transparency trackbar.</summary>
procedure FadeOut;
/// <summary>Finds the favourites list view item that is associated with
/// the favourite with the given snippet ID.</summary>
/// <remarks>Returns nil if no matching list item exists.</remarks>
function FindListItem(const SnippetID: TSnippetID): TListItem;
/// <summary>Records that a mouse button has been pressed over the
/// transparency trackbar and fades the form down to the transparency
/// specified by the trackbar.</summary>
procedure TBTransparencyMouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
/// <summary>Records that the currently depressed mouse button has been
/// released over the trackbar and fades the form back up to full
/// opacity.</summary>
procedure TBTransparencyMouseUp(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
strict protected
/// <summary>Configures some of the form's objects.</summary>
procedure ConfigForm; override;
/// <summary>Arranges and aligns the form's controls.</summary>
procedure ArrangeForm; override;
/// <summary>Initialises form's controls and restores last window position.
/// </summary>
procedure InitForm; override;
public
/// <summary>Displays and intialises the dialogue box non-modally, or
/// re-activates it if it is already displayed.</summary>
/// <param name="AOwner">TComponent [in] Reference to any owning component.
/// May be nil.</param>
/// <param name="Favourites">TFavourites [in] Reference to favourites
/// object to be displayed and managed.</param>
/// <param name="Notifier">INotifier [in] Reference to notifier object used
/// to cause a favourite snippet to be displayed in main window.</param>
class procedure Display(AOwner: TComponent; const Favourites: TFavourites;
Notifier: INotifier);
/// <summary>Closes the dialogue box, freeing any form instance.</summary>
class procedure Close;
/// <summary>Checks if the form is currently displayed.</summary>
class function IsDisplayed: Boolean;
end;
implementation
uses
// Delphi
SysUtils, DateUtils, Windows, Graphics,
// Project
DB.UMain, DB.USnippet, UCtrlArranger, UMessageBox, UPreferences, USettings,
UStructs, UStrUtils;
{$R *.dfm}
type
/// <summary>Custom list item class that adds ability to associate a
/// TFavourite record with list item.</summary>
TFavouriteListItem = class(TListItem)
strict private
var
/// <summary>Value of Favourite property.</summary>
fFavourite: TFavourite;
public
/// <summary>Favourite associated with list item.</summary>
property Favourite: TFavourite read fFavourite write fFavourite;
end;
type
/// <summary>Hack to enable OnMouseUp and OnMouseDown events of TTrackBar to
/// be set.</summary>
/// <remarks>For some reason these events are protected in TTrackBar.
/// </remarks>
TTrackBarHack = class(TTrackBar);
{ TFavouritesDlg }
procedure TFavouritesDlg.actDeleteAllExecute(Sender: TObject);
resourcestring
sQuery = 'Do you really want to delete all your favourites?';
begin
if TMessageBox.Confirm(Self, sQuery) then
begin
fLVFavs.Items.BeginUpdate;
try
fFavourites.Clear;
finally
fLVFavs.Items.EndUpdate;
end;
end;
end;
procedure TFavouritesDlg.actDeleteAllUpdate(Sender: TObject);
begin
actDeleteAll.Enabled := not fFavourites.IsEmpty;
end;
procedure TFavouritesDlg.actDeleteExecute(Sender: TObject);
var
LI: TFavouriteListItem;
begin
LI := fLVFavs.Selected as TFavouriteListItem;
fFavourites.Remove(LI.Favourite.SnippetID);
end;
procedure TFavouritesDlg.actDeleteUpdate(Sender: TObject);
begin
actDelete.Enabled := Assigned(fLVFavs.Selected);
end;
procedure TFavouritesDlg.actDisplayExecute(Sender: TObject);
var
LI: TFavouriteListItem;
SelectedSnippet: TSnippetID;
begin
LI := fLVFavs.Selected as TFavouriteListItem;
SelectedSnippet := LI.Favourite.SnippetID;
fNotifier.DisplaySnippet(
SelectedSnippet.Name,
SelectedSnippet.UserDefined,
chkNewTab.Checked
);
fFavourites.Touch(SelectedSnippet);
fLVFavs.Selected := FindListItem(SelectedSnippet);
end;
procedure TFavouritesDlg.actDisplayUpdate(Sender: TObject);
begin
actDisplay.Enabled := Assigned(fLVFavs.Selected);
end;
procedure TFavouritesDlg.AddLVItem(const Favourite: TFavourite);
var
LI: TFavouriteListItem;
Snippet: TSnippet;
begin
LI := fLVFavs.Items.Add as TFavouriteListItem;
Snippet := Database.Snippets.Find(Favourite.SnippetID);
if Assigned(Snippet) then
LI.Caption := Snippet.DisplayName
else
LI.Caption := Favourite.SnippetID.Name;
if IsToday(Favourite.LastAccessed) then
LI.SubItems.Add(TimeToStr(Favourite.LastAccessed))
else
LI.SubItems.Add(DateTimeToStr(Favourite.LastAccessed));
LI.Favourite := Favourite;
end;
procedure TFavouritesDlg.ArrangeForm;
begin
TCtrlArranger.AlignTops([fLVFavs, btnDisplay], 0);
TCtrlArranger.AlignLefts([fLVFavs, chkNewTab], 0);
TCtrlArranger.AlignLefts(
[btnDisplay, btnDelete, btnDeleteAll],
TCtrlArranger.RightOf(fLVFavs, 8)
);
TCtrlArranger.MoveBelow(fLVFavs, chkNewTab, 8);
pnlBody.ClientWidth := TCtrlArranger.TotalControlWidth(pnlBody) + 4;
pnlBody.ClientHeight := TCtrlArranger.TotalControlHeight(pnlBody);
inherited;
TCtrlArranger.AlignLefts([pnlBody, lblTransparency]);
TCtrlArranger.MoveToRightOf(lblTransparency, tbTransparency, 4);
TCtrlArranger.AlignTops([btnClose, lblTransparency, tbTransparency]);
end;
class procedure TFavouritesDlg.Close;
begin
if IsDisplayed then
FreeAndNil(fInstance);
end;
procedure TFavouritesDlg.ConfigForm;
begin
inherited;
fFavourites.AddListener(FavouritesListener);
TTrackBarHack(tbTransparency).OnMouseDown := TBTransparencyMouseDown;
TTrackBarHack(tbTransparency).OnMouseUp := TBTransparencyMouseUp;
end;
procedure TFavouritesDlg.CreateLV;
resourcestring
sSnippetName = 'Snippet';
sLastAccessed = 'Last used';
begin
fLVFavs := TListViewEx.Create(Self);
with fLVFavs do
begin
Parent := pnlBody;
Height := 240;
Width := 360;
HideSelection := False;
ReadOnly := True;
RowSelect := True;
TabOrder := 0;
TabStop := True;
ViewStyle := vsReport;
SortImmediately := False;
with Columns.Add do
begin
Caption := sSnippetName;
Width := 180;
end;
with Columns.Add do
begin
Caption := sLastAccessed;
Width := 140;
end;
OnDblClick := LVDoubleClick;
OnCompare := LVFavouritesCompare;
OnCreateItemClass := LVFavouriteCreateItemClass;
OnCustomDrawItem := LVCustomDrawItem;
OnCustomDrawSubItem := LVCustomDrawSubItem;
end;
end;
class procedure TFavouritesDlg.Display(AOwner: TComponent;
const Favourites: TFavourites; Notifier: INotifier);
begin
if not Assigned(fInstance) then
fInstance := Create(AOwner);
fInstance.fFavourites := Favourites;
fInstance.fNotifier := Notifier;
if not fInstance.Visible then
begin
fInstance.Show;
end;
fInstance.SetFocus;
end;
procedure TFavouritesDlg.FadeIn;
begin
FadeTo(High(Byte));
end;
procedure TFavouritesDlg.FadeOut;
begin
FadeTo(tbTransparency.Position);
end;
procedure TFavouritesDlg.FadeTo(const NewTransparency: Byte);
var
Step: Int8;
begin
Step := -1;
if AlphaBlendValue < NewTransparency then
Step := -Step;
while AlphaBlendValue <> NewTransparency do
begin
AlphaBlendValue := AlphaBlendValue + Step;
Sleep(2);
end;
end;
procedure TFavouritesDlg.FavouritesListener(Sender: TObject;
const EvtInfo: IInterface);
var
Evt: IFavouritesChangeEventInfo;
SelectedSnippet: TSnippetID;
HaveSelection: Boolean;
begin
Evt := EvtInfo as IFavouritesChangeEventInfo;
case Evt.Action of
cnAdded:
begin
HaveSelection := Assigned(fLVFavs.Selected);
if HaveSelection then
SelectedSnippet :=
(fLVFavs.Selected as TFavouriteListItem).Favourite.SnippetID;
AddLVItem(Evt.Favourite);
ReSortLV;
if HaveSelection then
fLVFavs.Selected := FindListItem(SelectedSnippet);
end;
cnRemoved:
begin
HaveSelection := Assigned(fLVFavs.Selected);
if HaveSelection then
SelectedSnippet :=
(fLVFavs.Selected as TFavouriteListItem).Favourite.SnippetID;
RemoveLVItem(Evt.Favourite);
ReSortLV;
if HaveSelection and (Evt.Favourite.SnippetID <> SelectedSnippet) then
fLVFavs.Selected := FindListItem(SelectedSnippet);
end;
end;
end;
function TFavouritesDlg.FindListItem(const SnippetID: TSnippetID): TListItem;
var
LI: TListItem;
begin
for LI in fLVFavs.Items do
begin
if (LI as TFavouriteListItem).Favourite.SnippetID = SnippetID then
Exit(LI);
end;
Result := nil;
end;
procedure TFavouritesDlg.FormActivate(Sender: TObject);
begin
FadeIn;
end;
procedure TFavouritesDlg.FormClose(Sender: TObject; var Action: TCloseAction);
begin
inherited;
fInstance := nil;
Action := caFree;
end;
procedure TFavouritesDlg.FormCreate(Sender: TObject);
begin
inherited;
CreateLV;
fOptions := TPersistentOptions.Create;
fWindowSettings := TDlgWindowSettings.CreateStandAlone(Self);
AlphaBlendValue := High(Byte);
end;
procedure TFavouritesDlg.FormDeactivate(Sender: TObject);
begin
FadeOut;
end;
procedure TFavouritesDlg.FormDestroy(Sender: TObject);
begin
fFavourites.RemoveListener(FavouritesListener);
fOptions.DisplayInNewTabs := chkNewTab.Checked;
fOptions.InactiveAlphaBlendValue := tbTransparency.Position;
fOptions.Free;
fWindowSettings.Save;
inherited;
end;
procedure TFavouritesDlg.InitForm;
begin
inherited;
fWindowSettings.Restore;
PopulateLV;
chkNewTab.Checked := fOptions.DisplayInNewTabs;
tbTransparency.OnChange := nil;
tbTransparency.Position := fOptions.InactiveAlphaBlendValue;
tbTransparency.OnChange := tbTransparencyChange;
end;
class function TFavouritesDlg.IsDisplayed: Boolean;
begin
Result := Assigned(fInstance) and fInstance.Visible;
end;
procedure TFavouritesDlg.LVCustomDrawItem(Sender: TCustomListView;
Item: TListItem; State: TCustomDrawState; var DefaultDraw: Boolean);
var
UserDefined: Boolean;
begin
UserDefined := (Item as TFavouriteListItem).Favourite.SnippetID.UserDefined;
fLVFavs.Canvas.Font.Color := Preferences.DBHeadingColours[UserDefined];
end;
procedure TFavouritesDlg.LVCustomDrawSubItem(Sender: TCustomListView;
Item: TListItem; SubItem: Integer; State: TCustomDrawState;
var DefaultDraw: Boolean);
begin
// required to force colour change on following line
fLVFavs.Canvas.Font.Color := clNone;
fLVFavs.Canvas.Font.Color := clWindowText;
end;
procedure TFavouritesDlg.LVDoubleClick(Sender: TObject);
begin
actDisplay.Execute;
end;
procedure TFavouritesDlg.LVFavouriteCreateItemClass(Sender: TCustomListView;
var ItemClass: TListItemClass);
begin
ItemClass := TFavouriteListItem;
end;
procedure TFavouritesDlg.LVFavouritesCompare(Sender: TObject; Item1,
Item2: TListItem; Data: Integer; var Compare: Integer);
var
Fav1, Fav2: TFavourite;
begin
case fLVFavs.SortColumn of
0:
// use item Caption here since it is set to snippet display name
// which is not recorded in the item's associated TFavourite record
Compare := StrCompareText(Item1.Caption, Item2.Caption);
1:
begin
Fav1 := (Item1 as TFavouriteListItem).Favourite;
Fav2 := (Item2 as TFavouriteListItem).Favourite;
Compare := CompareDateTime(Fav1.LastAccessed, Fav2.LastAccessed);
end;
end;
if fLVFavs.SortOrder = soDown then
Compare := -Compare;
end;
procedure TFavouritesDlg.PopulateLV;
var
Fav: TFavourite;
begin
fLVFavs.Clear;
for Fav in fFavourites do
AddLVItem(Fav);
fLVFavs.Selected := nil;
ReSortLV;
end;
procedure TFavouritesDlg.RemoveLVItem(const Favourite: TFavourite);
var
LI: TListItem;
begin
for LI in fLVFavs.Items do
begin
if (LI as TFavouriteListItem).Favourite.SnippetID = Favourite.SnippetID then
begin
LI.Free;
Exit;
end;
end;
end;
procedure TFavouritesDlg.ReSortLV;
begin
if fLVFavs.SortColumn <> -1 then
fLVFavs.CustomSort(nil, fLVFavs.SortColumn);
end;
procedure TFavouritesDlg.tbTransparencyChange(Sender: TObject);
begin
if fTrackBarKeyDown or fTrackBarMouseDown then
AlphaBlendValue := tbTransparency.Position;
end;
procedure TFavouritesDlg.tbTransparencyKeyDown(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
fTrackBarKeyDown := True;
FadeOut;
end;
procedure TFavouritesDlg.tbTransparencyKeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
FadeIn;
fTrackBarKeyDown := False;
end;
procedure TFavouritesDlg.TBTransparencyMouseDown(Sender: TObject;
Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
FadeOut;
fTrackBarMouseDown := True;
end;
procedure TFavouritesDlg.TBTransparencyMouseUp(Sender: TObject;
Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
fTrackBarMouseDown := False;
FadeIn;
end;
{ TFavouritesDlg.TPersistentOptions }
constructor TFavouritesDlg.TPersistentOptions.Create;
var
Section: ISettingsSection;
begin
inherited Create;
Section := Settings.ReadSection(ssFavourites);
fDisplayInNewTabs := Section.GetBoolean(DisplayInNewTabsKey, False);
fInactiveAlphaBlendValue := Section.GetInteger(
InactiveAlphaBlendValueKey, 160
);
end;
destructor TFavouritesDlg.TPersistentOptions.Destroy;
var
Section: ISettingsSection;
begin
Section := Settings.EmptySection(ssFavourites);
Section.SetBoolean(DisplayInNewTabsKey, fDisplayInNewTabs);
Section.SetInteger(InactiveAlphaBlendValueKey, fInactiveAlphaBlendValue);
Section.Save;
inherited;
end;
end.
