wxWidgets/include/wx/webview.h

/////////////////////////////////////////////////////////////////////////////
// Name:        webview.h
// Purpose:     Common interface and events for web view component
// Author:      Marianne Gagnon
// Id:          $Id$
// Copyright:   (c) 2010 Marianne Gagnon
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifndef _WX_WEB_VIEW_H_
#define _WX_WEB_VIEW_H_

#include "wx/setup.h"

#if wxUSE_WEB

#include <wx/control.h>
#include <wx/event.h>
#include <wx/sstream.h>
#include "wx/sharedptr.h"

class WXDLLIMPEXP_WEB wxWebHistoryItem
{
public:
    wxWebHistoryItem(const wxString& url, const wxString& title) : 
                     m_url(url), m_title(title) {}
    wxString GetUrl() { return m_url; }
    wxString GetTitle() { return m_title; }

private:
    wxString m_url, m_title;
};

/**
 * Zoom level in web view component
 */
enum wxWebViewZoom
{
    wxWEB_VIEW_ZOOM_TINY,
    wxWEB_VIEW_ZOOM_SMALL,
    wxWEB_VIEW_ZOOM_MEDIUM,
    wxWEB_VIEW_ZOOM_LARGE,
    wxWEB_VIEW_ZOOM_LARGEST
};

/**
 * The type of zooming that the web view control can perform
 */
enum wxWebViewZoomType
{
    /** The entire layout scales when zooming, including images */
    wxWEB_VIEW_ZOOM_TYPE_LAYOUT,
    /** Only the text changes in size when zooming, images and other layout
      * elements retain their initial size */
    wxWEB_VIEW_ZOOM_TYPE_TEXT
};

/** Types of errors that can cause navigation to fail */
enum wxWebNavigationError
{
    /** Connection error (timeout, etc.) */
    wxWEB_NAV_ERR_CONNECTION,
    /** Invalid certificate */
    wxWEB_NAV_ERR_CERTIFICATE,
    /** Authentication required */
    wxWEB_NAV_ERR_AUTH,
    /** Other security error */
    wxWEB_NAV_ERR_SECURITY,
    /** Requested resource not found */
    wxWEB_NAV_ERR_NOT_FOUND,
    /** Invalid request/parameters (e.g. bad URL, bad protocol,
      * unsupported resource type) */
    wxWEB_NAV_ERR_REQUEST,
    /** The user cancelled (e.g. in a dialog) */
    wxWEB_NAV_ERR_USER_CANCELLED,
    /** Another (exotic) type of error that didn't fit in other categories*/
    wxWEB_NAV_ERR_OTHER
};

/** Type of refresh */
enum wxWebViewReloadFlags
{
    /** Default reload, will access cache */
    wxWEB_VIEW_RELOAD_DEFAULT,
    /** Reload the current view without accessing the cache */
    wxWEB_VIEW_RELOAD_NO_CACHE 
};


/**
 * List of available backends for wxWebView
 */
enum wxWebViewBackend
{
    /** Value that may be passed to wxWebView to let it pick an appropriate
     * engine for the current platform*/
    wxWEB_VIEW_BACKEND_DEFAULT,

    /** The OSX-native WebKit web engine */
    wxWEB_VIEW_BACKEND_OSX_WEBKIT,

    /** The GTK port of the WebKit engine */
    wxWEB_VIEW_BACKEND_GTK_WEBKIT,

    /** Use Microsoft Internet Explorer as web engine */
    wxWEB_VIEW_BACKEND_IE
};

extern WXDLLIMPEXP_DATA_WEB(const char) wxWebViewNameStr[];
extern WXDLLIMPEXP_DATA_WEB(const char) wxWebViewDefaultURLStr[];

class WXDLLIMPEXP_WEB wxWebView : public wxControl
{
public:

    /**
     *  Creation function for two-step creation.
     */
    virtual bool Create(wxWindow* parent,
           wxWindowID id,
           const wxString& url,
           const wxPoint& pos,
           const wxSize& size,
           long style,
           const wxString& name) = 0;

    /**
     * Factory function to create a new wxWebView for two-step creation
     * (you need to call wxWebView::Create on the returned object)
     * @param backend which web engine to use as backend for wxWebView
     * @return the created wxWebView, or NULL if the requested backend is
     *         not available
     */
    static wxWebView* New(wxWebViewBackend backend = wxWEB_VIEW_BACKEND_DEFAULT);

    // TODO: clarify what styles can do, or remove this flag
    /**
     * Factory function to create a new wxWebView
     * @param parent parent window to create this view in
     * @param id ID of this control
     * @param url URL to load by default in the web view
     * @param pos position to create this control at
     *            (you may use wxDefaultPosition if you use sizers)
     * @param size size to create this control with
     *             (you may use wxDefaultSize if you use sizers)
     * @param backend which web engine to use as backend for wxWebView
     * @return the created wxWebView, or NULL if the requested backend
     *         is not available
     */
    static wxWebView* New(wxWindow* parent,
           wxWindowID id,
           const wxString& url = wxWebViewDefaultURLStr,
           const wxPoint& pos = wxDefaultPosition,
           const wxSize& size = wxDefaultSize,
           wxWebViewBackend backend = wxWEB_VIEW_BACKEND_DEFAULT,
           long style = 0,
           const wxString& name = wxWebViewNameStr);


    /** Get whether it is possible to navigate back in the history of
      * visited pages
      */
    virtual bool CanGoBack() = 0;

    /** Get whether it is possible to navigate forward in the history of
      * visited pages
      */
    virtual bool CanGoForward() = 0;

    /** Navigate back in the history of visited pages.
      * Only valid if CanGoBack() returned true.
      */
    virtual void GoBack() = 0;

    /** Navigate forwardin the history of visited pages.
      * Only valid if CanGoForward() returned true.
      */
    virtual void GoForward() = 0;

    /**
     * Load a HTMl document (web page) from a URL
     * @param url the URL where the HTML document to display can be found
     * @note web engines generally report errors asynchronously, so if you wish
     *       to know whether loading the URL was successful, register to receive
     *       navigation error events
     */
    virtual void LoadUrl(const wxString& url) = 0;

    virtual void ClearHistory() = 0;
    virtual void EnableHistory(bool enable = true) = 0;
    virtual wxVector<wxSharedPtr<wxWebHistoryItem> > GetBackwardHistory() = 0;
    virtual wxVector<wxSharedPtr<wxWebHistoryItem> > GetForwardHistory() = 0;
    virtual void LoadHistoryItem(wxSharedPtr<wxWebHistoryItem> item) = 0;

    /**
     * Stop the current page loading process, if any.
     * May trigger an error event of type wxWEB_NAV_ERR_USER_CANCELLED.
     * TODO: make wxWEB_NAV_ERR_USER_CANCELLED errors uniform across ports.
     */
    virtual void Stop() = 0;

    /**
     * Reload the currently displayed URL.
     * @param flags A bit array that may optionnally contain reload options
     */
    virtual void Reload(wxWebViewReloadFlags flags = wxWEB_VIEW_RELOAD_DEFAULT) = 0;


    /**
     * Get the URL of the currently displayed document
     */
    virtual wxString GetCurrentURL() = 0;

    /**
     * Get the title of the current web page, or its URL/path if title is not
     * available
     */
    virtual wxString GetCurrentTitle() = 0;

    // TODO: handle choosing a frame when calling GetPageSource()?
    /**
     * Get the HTML source code of the currently displayed document
     * @return the HTML source code, or an empty string if no page is currently
     *         shown
     */
    virtual wxString GetPageSource() = 0;

   /**
     * Get the zoom factor of the page
     * @return How much the HTML document is zoomed (scaleed)
     */
    virtual wxWebViewZoom GetZoom() = 0;

    /**
     * Set the zoom factor of the page
     * @param zoom How much to zoom (scale) the HTML document
     */
    virtual void SetZoom(wxWebViewZoom zoom) = 0;

    /**
     * Set how to interpret the zoom factor
     * @param zoomType how the zoom factor should be interpreted by the
     *                 HTML engine
     * @note invoke    canSetZoomType() first, some HTML renderers may not
     *                 support all zoom types
     */
    virtual void SetZoomType(wxWebViewZoomType zoomType) = 0;

    /**
     * Get how the zoom factor is currently interpreted
     * @return how the zoom factor is currently interpreted by the HTML engine
     */
    virtual wxWebViewZoomType GetZoomType() const = 0;

    /**
     * Retrieve whether the current HTML engine supports a type of zoom
     * @param type the type of zoom to test
     * @return whether this type of zoom is supported by this HTML engine
     *         (and thus can be set through setZoomType())
     */
    virtual bool CanSetZoomType(wxWebViewZoomType type) const = 0;

    // TODO: allow 'SetPage' to find files (e.g. images) from a virtual file
    // system if possible
    /**
     * Set the displayed page source to the contents of the given string
     * @param html    the string that contains the HTML data to display
     * @param baseUrl URL assigned to the HTML data, to be used to resolve
     *                relative paths, for instance
     */
    virtual void SetPage(const wxString& html, const wxString& baseUrl) = 0;

    /**
     * Set the displayed page source to the contents of the given stream
     * @param html    the stream to read HTML data from
     * @param baseUrl URL assigned to the HTML data, to be used to resolve
     *                relative paths, for instance
     */
    virtual void SetPage(wxInputStream& html, wxString baseUrl)
    {
        wxStringOutputStream stream;
        stream.Write(html);
        SetPage(stream.GetString(), baseUrl);
    }

    // TODO:
    //     wxString GetSelection();                         // maybe?
    //     void SetSelection(...);                          // maybe?

    //     void MakeEditable(bool enable = true);           // maybe?
    //     bool IsEditable();                               // maybe?

    //     void EnableJavascript(bool enabled);             // maybe?
    //     wxString RunScript(const wxString& javascript);  // maybe?

    //     void SetScrollPos(int pos);                      // maybe?
    //     int GetScrollPos();                              // maybe?

    //     wxString GetStatusText();                        // maybe?
    //     void SetStatusText(wxString text);               // maybe?
    //     * status text changed event?
    //     * title changed event?

    //    virtual bool IsOfflineMode() = 0;                 // maybe?
    //     virtual void SetOfflineMode(bool offline) = 0;   // maybe?

    // TODO: offer API to control the opening of new frames
    //       (through <a target="..."> as well as through javascript), OR
    //       provide a behavior consistent across ports.
    // - OSX : I receive an event for new frames opened with HTML target, and
    //           currently block them all.
    // - IE  : An event is recieved for new frames and they are currently 
    //           blocked
    // - GTK : All frame open requests are blocked. A slot exists that I could
    //           connect to to be notified if ever needed

    /**
     * Opens a print dialog so that the user may print the currently
     * displayed page.
     */
    virtual void Print() = 0;

    /**
     * Returns whether the web control is currently busy (e.g. loading a page)
     */
    virtual bool IsBusy() = 0;
};

class WXDLLIMPEXP_WEB wxWebNavigationEvent : public wxCommandEvent
{
public:
    wxWebNavigationEvent() {}
    wxWebNavigationEvent(wxEventType type, int id, const wxString href,
                         const wxString target, bool canVeto)
        : wxCommandEvent(type, id)
    {
        m_href = href;
        m_target = target;
        m_vetoed = false;
        m_canVeto = canVeto;
    }

    /**
     *  Get the URL being visited
     */
    const wxString& GetHref() const { return m_href; }

    /**
     * Get the target (frame or window) in which the URL that caused this event
     * is viewed, or an empty string if not available.
     */
    const wxString& GetTarget() const { return m_target; }

    // default copy ctor, assignment operator and dtor are ok
    virtual wxEvent* Clone() const { return new wxWebNavigationEvent(*this); }

    /** Get whether this event may be vetoed (stopped/prevented). Only
      *  meaningful for events fired before navigation takes place.
      */
    bool CanVeto() const { return m_canVeto; }

    /** Whether this event was vetoed (stopped/prevented). Only meaningful for
     *  events fired before navigation takes place.
     */
    bool IsVetoed() const { return m_vetoed; }

    /** Veto (prevent/stop) this event. Only meaningful for events fired
     *  before navigation takes place. Only valid if CanVeto() returned true.
     */
    void Veto() { wxASSERT(m_canVeto); m_vetoed = true; }

private:
    wxString m_href;
    wxString m_target;
    bool m_canVeto;
    bool m_vetoed;

    wxDECLARE_DYNAMIC_CLASS_NO_ASSIGN(wxWebNavigationEvent);
};

wxDECLARE_EXPORTED_EVENT( WXDLLIMPEXP_WEB, wxEVT_COMMAND_WEB_VIEW_NAVIGATING, wxWebNavigationEvent );
wxDECLARE_EXPORTED_EVENT( WXDLLIMPEXP_WEB, wxEVT_COMMAND_WEB_VIEW_NAVIGATED, wxWebNavigationEvent );
wxDECLARE_EXPORTED_EVENT( WXDLLIMPEXP_WEB, wxEVT_COMMAND_WEB_VIEW_LOADED, wxWebNavigationEvent );
wxDECLARE_EXPORTED_EVENT( WXDLLIMPEXP_WEB, wxEVT_COMMAND_WEB_VIEW_ERROR, wxWebNavigationEvent );
wxDECLARE_EXPORTED_EVENT( WXDLLIMPEXP_WEB, wxEVT_COMMAND_WEB_VIEW_NEWWINDOW, wxWebNavigationEvent );

typedef void (wxEvtHandler::*wxWebNavigationEventFunction)
             (wxWebNavigationEvent&);

#define wxWebNavigationEventHandler(func) \
    wxEVENT_HANDLER_CAST(wxWebNavigationEventFunction, func)

#define EVT_WEB_VIEW_NAVIGATING(id, fn) \
    wx__DECLARE_EVT1(wxEVT_COMMAND_WEB_VIEW_NAVIGATING, id, \
                     wxHtmlNavigatingEventHandler(fn))

#define EVT_WEB_VIEW_NAVIGATED(id, fn) \
    wx__DECLARE_EVT1(wxEVT_COMMAND_WEB_VIEW_NAVIGATED, id, \
                     wxHtmlNavigatingEventHandler(fn))

#define EVT_WEB_VIEW_LOADED(id, fn) \
    wx__DECLARE_EVT1(wxEVT_COMMAND_WEB_VIEW_LOADED, id, \
                     wxHtmlNavigatingEventHandler(fn))

#define EVT_WEB_VIEW_ERRROR(id, fn) \
    wx__DECLARE_EVT1(wxEVT_COMMAND_WEB_VIEW_ERROR, id, \
                     wxHtmlNavigatingEventHandler(fn))

#define EVT_WEB_VIEW_NEWWINDOW(id, fn) \
    wx__DECLARE_EVT1(wxEVT_COMMAND_WEB_VIEW_NEWWINDOW, id, \
                     wxHtmlNavigatingEventHandler(fn))

#endif // wxUSE_WEB

#endif // _WX_WEB_VIEW_H_