{
* 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) 2007-2013, Peter Johnson (www.delphidabbler.com).
*
* $Rev$
* $Date$
*
* Defines various classes used to configure one or more command bars owned by
* a web browser container. Command bars are UI elements used to issue commands,
* e.g. menus & toolbars.
}
unit UWBCommandBars;
interface
uses
// Delphi
ImgList, Menus,
// Project
UCommandBars, UDispatchList, UGIFImageList;
type
/// <summary>
/// Command bar manager for use with command bars associated with web browser
/// controls.
/// </summary>
/// <remarks>
/// All instances share the same, static, image list.
/// </remarks>
TWBCommandBarMgr = class sealed(TCommandBarMgr, ICommandBarConfig)
strict private
class var
/// <summary>Static image list.</summary>
fImages: TGIFImageList;
public
/// <summary>Creates empty static image list.</summary>
class constructor Create;
/// <summary>Frees static image list.</summary>
class destructor Destroy;
/// <summary>Sets image list to be used by all command bars to given image
/// list.</summary>
/// <remarks>
/// <para>Assigns images from Images to static image list.</para>
/// <para>Method of ICommandBarConfig.</para>
/// </remarks>
procedure SetImages(const Images: TCustomImageList); override;
end;
type
/// <summary>
/// Wrapper for popup menus associated with a web browser control. Records
/// reference HTML element under mouse cursor and prevents display of menu if
/// there's nothing to display.
/// </summary>
TWBPopupMenuWrapper = class(TPopupMenuWrapper)
strict private
/// <summary>Checks if menu has any visible non-spacer menu items with
/// captions.</summary>
/// <remarks>Assumes there are no sub-menus.</remarks>
function HasVisibleItems: Boolean;
/// <summary>Handles wrapped menu's OnPopupQuery event. Prevents display of
/// menu if there are no displayable items.</summary>
/// <param name="Sender">TObject [in] Not used.</param>
/// <param name="Cancel">Boolean [in/out] False when method called. Set to
/// True if menu is not to be displayed.</param>
procedure QueryPopupHandler(Sender: TObject; var Cancel: Boolean);
strict protected
/// <summary>Initialises menu. Records details of HTML link element in any
/// link related menu items.</summary>
procedure InitMenu; override;
public
/// <summary>Sets up object for a given popup menu.</summary>
constructor Create(const Menu: TPopupMenu); override;
end;
type
/// <summary>
/// Wrapper for popup menus associated with a web browser control. Extends
/// TWBPopupMenuWrapper to add some menu items based on links in underlying
/// document in browser control.
/// </summary>
TWBDefaultPopupMenuWrapper = class sealed(TWBPopupMenuWrapper)
strict private
/// <summary>Clears temporary menu items from menu.</summary>
procedure ClearTempMenuItems;
/// <summary>Gets all command and help links from browser document that are
/// designated as menu items.</summary>
/// <param name="Doc">IDispatch [in] IDispatch interface of document
/// containing links.</param>
/// <param name="CommandItems">IDispatchLIst [out] List of command links.
/// </param>
/// <param name="HelpItems">IDispatchList [out] List of help links.</param>
procedure GetLinkMenuItems(const Doc: IDispatch; out CommandItems,
HelpItems: IDispatchList);
/// <summary>Adds menu items to menu that can trigger links from a link
/// list.</summary>
/// <param name="Links">IDispatchList [in] List of links to be added to
/// name.</param>
procedure AddLinksToMenu(const Links: IDispatchList);
/// <summary>Gets index of any image associated with a link in image list
/// used by menu. If image doesn't exist in list it is added to it.
/// </summary>
/// <param name="Link">IDispatch [in] Link for which image needed.</param>
/// <returns>Index of image in image list or -1 if there is no associated
/// image.</returns>
function GetImageIndex(const Link: IDispatch): Integer;
strict protected
/// <summary>Initialises menu. Clears temporary menu items and adds any
/// required menu items for links in HTML document.</summary>
procedure InitMenu; override;
end;
implementation
uses
// Project
UAnchors, UHTMLDOMHelper, UImageTags, ULinkAction, UMenus, UStrUtils,
UWBPopupMenus;
{ TWBCommandBarMgr }
class constructor TWBCommandBarMgr.Create;
begin
fImages := TGIFImageList.Create(nil);
end;
class destructor TWBCommandBarMgr.Destroy;
begin
fImages.Free;
end;
procedure TWBCommandBarMgr.SetImages(const Images: TCustomImageList);
begin
fImages.Clear;
fImages.AddImages(Images);
inherited SetImages(fImages);
end;
{ TWBPopupMenuWrapper }
constructor TWBPopupMenuWrapper.Create(const Menu: TPopupMenu);
begin
inherited;
// Assign popup query handler if possible
if (Menu is TWBPopupMenu) then
(Menu as TWBPopupMenu).OnQueryPopup := QueryPopupHandler;
end;
function TWBPopupMenuWrapper.HasVisibleItems: Boolean;
var
MI: TMenuItem; // each menu item in menu
begin
Result := False;
for MI in Menu.Items do
if MI.Visible and (MI.Caption <> '') and (MI.Caption <> '-') then
begin
Result := True;
Exit;
end;
end;
procedure TWBPopupMenuWrapper.InitMenu;
var
MI: TMenuItem; // references a menu item
begin
for MI in Menu.Items do
if MI.Action is TLinkAction then
// menu item associated with a link action: store reference to Elem in it
(MI.Action as TLinkAction).Link := (Menu as TWBPopupMenu).HTMLElem;
end;
procedure TWBPopupMenuWrapper.QueryPopupHandler(Sender: TObject;
var Cancel: Boolean);
begin
PrepareMenu;
Cancel := not HasVisibleItems;
end;
{ TWBDefaultPopupMenuWrapper }
procedure TWBDefaultPopupMenuWrapper.AddLinksToMenu(const Links: IDispatchList);
var
Action: TLinkAction; // action to trigger a link
Link: IDispatch; // references all links in Links
begin
// Do nothing if list is empty
if Links.Count = 0 then
Exit;
// Start list with a spacer
Menu.Items.Add(CreateMenuSpacer(Menu, TWBTempMenuItem));
// Add menu items
for Link in Links do
begin
// Create action for menu item: store link reference and get caption from
// link text. If link is not visible it is not added to menu.
if THTMLDOMHelper.ElemIsVisible(Link) then
begin
Action := TLinkAction.Create(nil);
Action.Link := Link;
Action.ImageIndex := GetImageIndex(Link);
Action.Caption := TAnchors.GetInnerText(Link);
Menu.Items.Add(CreateMenuItem(Menu, TWBTempMenuItem, Action));
end;
end;
end;
procedure TWBDefaultPopupMenuWrapper.ClearTempMenuItems;
var
MI: TMenuItem; // references each menu item in menu
Idx: Integer; // loops through all menu items
begin
// NOTE: do not use enumerator here: goes horribly wrong since MI is freed.
for Idx := Pred(Menu.Items.Count) downto 0 do
begin
MI := Menu.Items[Idx];
if MI is TWBTempMenuItem then
MI.Free;
end;
end;
function TWBDefaultPopupMenuWrapper.GetImageIndex(
const Link: IDispatch): Integer;
/// Extracts a base resource name from a URL.
function URLBaseName(const URL: string): string;
var
Pos: Integer; // position of last path delimiter in URL
begin
Pos := StrLastDelimiterPos('/', URL);
if Pos > 0 then
Result := StrSliceRight(URL, Length(URL) - Pos)
else
Result := URL;
end;
var
ParentDiv: IDispatch; // parent <div> or <span> tag that contains Link
ImgTags: IDispatchList; // all <img> children of parent
ImgTag: IDispatch; // <img> child of parent that contains required GIF
Src: string; // resource URL of GIF file
begin
Result := -1;
// Check if parent elem is a <div> or <span> with class "option"
ParentDiv := THTMLDOMHelper.ParentElem(Link, 'div', 'option');
if not Assigned(ParentDiv) then
ParentDiv := THTMLDOMHelper.ParentElem(Link, 'span', 'option');
if not Assigned(ParentDiv) then
Exit;
// So see if there's an child <img> of parent with class "option-img"
ImgTags := TImageTags.GetAllImageTags(ParentDiv);
ImgTag := nil;
for ImgTag in ImgTags do
if THTMLDOMHelper.ElemHasClass(ImgTag, 'option-img') then
Break;
if not Assigned(ImgTag) then
Exit;
// Get resource name of image from <img> tag's "src" attribute
Src := URLBaseName(TImageTags.GetSrc(ImgTag));
// Get matching bitmap from image list: add one from GIF file if not found
Result := -1;
if Menu.Images is TGIFImageList then
with Menu.Images as TGIFImageList do
begin
Result := ImageIndex(Src);
if Result = -1 then
Result := AddGIFImage(Src);
end;
end;
procedure TWBDefaultPopupMenuWrapper.GetLinkMenuItems(const Doc: IDispatch;
out CommandItems, HelpItems: IDispatchList);
var
AllLinks: IDispatchList; // list of all links in document
Link: IDispatch; // referenced each link in AllLinks
begin
CommandItems := TDispatchList.Create;
HelpItems := TDispatchList.Create;
// Get all links from document
AllLinks := TAnchors.GetAllAnchors(Doc);
// Scan all links
for Link in AllLinks do
begin
// To have a link on menu it must have 'menu-item' class
if THTMLDOMHelper.ElemHasClass(Link, 'menu-item') then
begin
case TAnchors.AnchorKind(Link) of
akCommand:
CommandItems.Add(Link);
akHelp:
HelpItems.Add(Link);
end;
end;
end;
end;
procedure TWBDefaultPopupMenuWrapper.InitMenu;
var
CommandLinks: IDispatchList; // list of command links in document
HelpLinks: IDispatchList; // list of help links in document
begin
// Removes any pre-existing menu items from menu
ClearTempMenuItems;
inherited;
// Get list of command and help links from current document
GetLinkMenuItems(
THTMLDOMHelper.DocumentFromElem(
(Menu as TWBPopupMenu).HTMLElem
),
CommandLinks,
HelpLinks
);
// Add the required menu items to the menu
AddLinksToMenu(CommandLinks);
AddLinksToMenu(HelpLinks);
end;
end.
