{
* 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) 2009-2013, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Implements class that manages check list box controls that display lists of
* Delphi units. Builds expandable list, sets check marks for specified units
* and gets list of checked units.
}
unit UUnitsChkListMgr;
interface
uses
// Delphi
Classes, CheckLst, Controls,
// Project
UIStringList;
type
/// <summary>Manages check list box controls that display lists of Delphi
/// units. Unit list is persisted.</summary>
TUnitsChkListMgr = class(TObject)
strict private
var
/// <summary>Check list box being managed.</summary>
fCLB: TCheckListBox;
/// <summary>List of reserved unit names.</summary>
/// <remarks>Deafult units can't be deleted from list.</remarks>
fReservedUnits: IStringList;
/// <summary>List of default unit names.</summary>
/// <remarks>Default units are those non-reserved units added to list
/// when user has not specified any units or requests restoration of
/// defaults.</remarks>
fDefaultUnits: IStringList;
/// <summary>Traps check list box's OnMouseDown event to ensure right
/// click selects list item under mouse.</summary>
procedure MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
/// <summary>Initialises unit list with reserved and any stored units.
/// </summary>
procedure InitList;
/// <summary>Saves any non-reserved units to storage.</summary>
procedure SaveList;
public
/// <summary>Constructs manager object for given check list box and loads
/// units from persistent storage.</summary>
constructor Create(const CLB: TCheckListBox);
/// <summary>Destroys manager object and updates persistent storage.
/// </summary>
destructor Destroy; override;
/// <summary>Checks if given unit name is valid.</summary>
function IsValidUnitName(const UnitName: string): Boolean;
/// <summary>Checks if given unit name is contained in the list.</summary>
function ContainsUnit(const UnitName: string): Boolean;
/// <summary>Ensures that a unit name is included in the list.</summary>
/// <param name="UnitName">string [in] Name of unit to be included. It is
/// added to the list unless already present.</param>
/// <param name="Checked">Boolean [in] Determines whether named unit is to
/// be checked.</param>
procedure IncludeUnit(const UnitName: string; const Checked: Boolean);
/// <summary>Ensures all the given units are include in the list.</summary>
/// <param name="Units">IStringList [in] List of unit names to be included.
/// Each is added to the list unless already present.</param>
/// <param name="Checked">Boolean [in] Determines whether each unit is to
/// be checked.</param>
procedure IncludeUnits(Units: IStringList; const Checked: Boolean);
/// <summary>Returns a list of names of all checked units in list box.
/// </summary>
function GetCheckedUnits: IStringList;
/// <summary>Checks if currently selected unit can be removed from list.
/// </summary>
/// <remarks>Returns False if there is no selection.</remarks>
function CanDeleteSelectedItem: Boolean;
/// <summary>Deletes currently selected unot from list if possible.
/// </summary>
/// <remarks>Does nothing if no selection or if selected unit can't be
/// deleted.</remarks>
procedure DeleteSelectedItem;
/// <summary>Restores default unit list.</summary>
procedure RestoreDefaults;
/// <summary>Clears checks from all items in list box.</summary>
procedure ClearChecks;
/// <summary>Tests if any items in list box are checked.</summary>
function HasCheckedItems: Boolean;
end;
implementation
uses
// Delphi
SysUtils, Types {for inlining},
// Project
USettings;
{ TUnitsChkListMgr }
function TUnitsChkListMgr.CanDeleteSelectedItem: Boolean;
var
Idx: Integer;
begin
Idx := fCLB.ItemIndex;
if (Idx < 0) or (Idx >= fCLB.Count) then
Exit(False);
Result := not fReservedUnits.Contains(fCLB.Items[Idx]);
end;
procedure TUnitsChkListMgr.ClearChecks;
var
Idx: Integer; // loops through all items in check list box
begin
for Idx := 0 to Pred(fCLB.Count) do
fCLB.Checked[Idx] := False;
end;
function TUnitsChkListMgr.ContainsUnit(const UnitName: string): Boolean;
begin
Result := fCLB.Items.IndexOf(UnitName) >= 0;
end;
constructor TUnitsChkListMgr.Create(const CLB: TCheckListBox);
begin
inherited Create;
fCLB := CLB;
fCLB.OnMouseDown := MouseDown;
fReservedUnits := TIStringList.Create(
['SysUtils', 'Classes', 'Windows', 'Graphics']
);
fDefaultUnits := TIStringList.Create(
['Controls', 'Messages', 'Types', 'ShlObj', 'ShellAPI', 'ActiveX', 'Math']
);
InitList;
end;
procedure TUnitsChkListMgr.DeleteSelectedItem;
begin
if not CanDeleteSelectedItem then
Exit;
fCLB.Items.Delete(fCLB.ItemIndex);
end;
destructor TUnitsChkListMgr.Destroy;
begin
SaveList;
inherited;
end;
function TUnitsChkListMgr.GetCheckedUnits: IStringList;
var
Idx: Integer; // loops through all listbox items
begin
Result := TIStringList.Create;
for Idx := 0 to Pred(fCLB.Items.Count) do
if fCLB.Checked[Idx] then
Result.Add(fCLB.Items[Idx]);
end;
function TUnitsChkListMgr.HasCheckedItems: Boolean;
var
Idx: Integer; // lopps thru each item in check list box
begin
for Idx := 0 to Pred(fCLB.Count) do
if fCLB.Checked[Idx] then
Exit(True);
Result := False;
end;
procedure TUnitsChkListMgr.IncludeUnit(const UnitName: string;
const Checked: Boolean);
var
UnitIndex: Integer; // index of unit name in list (-1 if not found)
begin
Assert(UnitName <> '', ClassName + '.IncludeUnit: UnitName is empty');
Assert(IsValidUnitName(UnitName),
ClassName + '.IncludeUnit: UnitName is not valid');
UnitIndex := fCLB.Items.IndexOf(UnitName);
if UnitIndex = -1 then
UnitIndex := fCLB.Items.Add(UnitName);
fCLB.Checked[UnitIndex] := Checked;
end;
procedure TUnitsChkListMgr.IncludeUnits(Units: IStringList;
const Checked: Boolean);
var
UnitName: string; // name of each unit in list
begin
for UnitName in Units do
IncludeUnit(UnitName, Checked);
end;
procedure TUnitsChkListMgr.InitList;
var
StoredUnits: IStringList;
Storage: ISettingsSection;
begin
fReservedUnits.CopyTo(fCLB.Items, True);
Storage := Settings.ReadSection(ssUnits);
if Storage.ItemCount > 0 then
begin
StoredUnits := Storage.GetStrings('Count', 'Unit%d');
if StoredUnits.Count > 0 then
StoredUnits.CopyTo(fCLB.Items, False);
end
else
fDefaultUnits.CopyTo(fCLB.Items, False);
end;
function TUnitsChkListMgr.IsValidUnitName(const UnitName: string): Boolean;
begin
Result := IsValidIdent(UnitName, True); // allow dots in unit name
end;
procedure TUnitsChkListMgr.MouseDown(Sender: TObject; Button: TMouseButton;
Shift: TShiftState; X, Y: Integer);
begin
if Button <> mbLeft then
fCLB.ItemIndex := fCLB.ItemAtPos(Point(X, Y), True);
end;
procedure TUnitsChkListMgr.RestoreDefaults;
var
CheckedUnits: IStringList; // list of checked units before restoration
SelectedUnit: string; // name of any selected unit before restoration
U: string; // each unit in CheckedUnits
Idx: Integer; // index of each U in restored list
begin
// record any checked and SelectedUnit units
CheckedUnits := GetCheckedUnits;
if fCLB.ItemIndex >= 0 then
SelectedUnit := fCLB.Items[fCLB.ItemIndex]
else
SelectedUnit := '';
// replace list box contents with default
fReservedUnits.CopyTo(fCLB.Items, True); // overwrites existing list
fDefaultUnits.CopyTo(fCLB.Items, False);
// restore any checks and selected item if still present
for U in CheckedUnits do
begin
Idx := fCLB.Items.IndexOf(U);
if Idx >= 0 then
fCLB.Checked[Idx] := True;
end;
fCLB.ItemIndex := fCLB.Items.IndexOf(SelectedUnit);
end;
procedure TUnitsChkListMgr.SaveList;
var
Storage: ISettingsSection;
U: string;
CustomUnits: IStringList;
begin
CustomUnits := TIStringList.Create;
for U in fCLB.Items do
if not fReservedUnits.Contains(U) then
CustomUnits.Add(U);
Storage := Settings.EmptySection(ssUnits);
Storage.SetStrings('Count', 'Unit%d', CustomUnits);
Storage.Save;
end;
end.
