GDK 事件类型

下列的数据类型被 GTK+ 传递给事件处理函数。列出每种数据类型同时也列出了使用该类型的信号。

• GdkEvent

  • drag_end_event

• GdkEventType

• GdkEventAny

  • delete_event

  • destroy_event

  • map_event

  • unmap_event

  • no_expose_event

• GdkEventExpose

  • expose_event

• GdkEventNoExpose

• GdkEventVisibility

• GdkEventMotion

  • motion_notify_event

• GdkEventButton

  • button_press_event

  • button_release_event

• GdkEventKey

  • key_press_event

  • key_release_event

• GdkEventCrossing

  • enter_notify_event

  • leave_notify_event

• GdkEventFocus

  • focus_in_event

  • focus_out_event

• GdkEventConfigure

  • configure_event

• GdkEventProperty

  • property_notify_event

• GdkEventSelection

  • selection_clear_event

  • selection_request_event

  • selection_notify_event

• GdkEventProximity

  • proximity_in_event

  • proximity_out_event

• GdkEventDragBegin

  • drag_begin_event

• GdkEventDragRequest

  • drag_request_event

• GdkEventDropEnter

  • drop_enter_event

• GdkEventDropLeave

  • drop_leave_event

• GdkEventDropDataAvailable

  • drop_data_available_event

• GdkEventClient

  • client_event

• GdkEventOther

  • other_event

数据类型GdkEventType是一个特殊的数据类型，它被其余的数据类型使用，作为一个传递给信号处理函数的数据类型指示器。在下面你会看到，每个事件数据结构有一个该类型的成员。它是如下的枚举值：

typedef enum
{
  GDK_NOTHING           = -1,
  GDK_DELETE            = 0,
  GDK_DESTROY           = 1,
  GDK_EXPOSE            = 2,
  GDK_MOTION_NOTIFY     = 3,
  GDK_BUTTON_PRESS      = 4,
  GDK_2BUTTON_PRESS     = 5,
  GDK_3BUTTON_PRESS     = 6,
  GDK_BUTTON_RELEASE    = 7,
  GDK_KEY_PRESS         = 8,
  GDK_KEY_RELEASE       = 9,
  GDK_ENTER_NOTIFY      = 10,
  GDK_LEAVE_NOTIFY      = 11,
  GDK_FOCUS_CHANGE      = 12,
  GDK_CONFIGURE         = 13,
  GDK_MAP               = 14,
  GDK_UNMAP             = 15,
  GDK_PROPERTY_NOTIFY   = 16,
  GDK_SELECTION_CLEAR   = 17,
  GDK_SELECTION_REQUEST = 18,
  GDK_SELECTION_NOTIFY  = 19,
  GDK_PROXIMITY_IN      = 20,
  GDK_PROXIMITY_OUT     = 21,
  GDK_DRAG_BEGIN        = 22,
  GDK_DRAG_REQUEST      = 23,
  GDK_DROP_ENTER        = 24,
  GDK_DROP_LEAVE        = 25,
  GDK_DROP_DATA_AVAIL   = 26,
  GDK_CLIENT_EVENT      = 27,
  GDK_VISIBILITY_NOTIFY = 28,
  GDK_NO_EXPOSE         = 29,
  GDK_OTHER_EVENT       = 9999  /* 不赞成使用，用过虑器代替 */
} GdkEventType;

剩下的，与其余事件类型不同的是GdkEvent。它是所有其余数据类型的统一，允许在一个信号处理函数中转换为指定的事件数据类型。

因此，事件类型有如下定义：

struct _GdkEventAny
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
};

struct _GdkEventExpose
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  GdkRectangle area;
  gint count; /* 如果非零，它是跟随事件的数目。*/
};

struct _GdkEventNoExpose
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  /* XXX: 有人需要X major_code或minor_code域吗？*/
};

struct _GdkEventVisibility
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  GdkVisibilityState state;
};

struct _GdkEventMotion
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 time;
  gdouble x;
  gdouble y;
  gdouble pressure;
  gdouble xtilt;
  gdouble ytilt;
  guint state;
  gint16 is_hint;
  GdkInputSource source;
  guint32 deviceid;
  gdouble x_root, y_root;
};

struct _GdkEventButton
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 time;
  gdouble x;
  gdouble y;
  gdouble pressure;
  gdouble xtilt;
  gdouble ytilt;
  guint state;
  guint button;
  GdkInputSource source;
  guint32 deviceid;
  gdouble x_root, y_root;
};

struct _GdkEventKey
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 time;
  guint state;
  guint keyval;
  gint length;
  gchar *string;
};

struct _GdkEventCrossing
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  GdkWindow *subwindow;
  GdkNotifyType detail;
};

struct _GdkEventFocus
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  gint16 in;
};

struct _GdkEventConfigure
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  gint16 x, y;
  gint16 width;
  gint16 height;
};

struct _GdkEventProperty
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  GdkAtom atom;
  guint32 time;
  guint state;
};

struct _GdkEventSelection
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  GdkAtom selection;
  GdkAtom target;
  GdkAtom property;
  guint32 requestor;
  guint32 time;
};

/* 这个事件数据类型很少用。它在支持XInput的程序中，用于绘制自己的光标 */

struct _GdkEventProximity
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 time;
  GdkInputSource source;
  guint32 deviceid;
};

struct _GdkEventDragRequest
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 requestor;
  union {
    struct {
      guint protocol_version:4;
      guint sendreply:1;
      guint willaccept:1;
      guint delete_data:1; 
      guint senddata:1;
      guint reserved:22;
    } flags;
    glong allflags;
  } u;
  guint8 isdrop; /* 几个 X 事件能产生这个gdk事件---这让应用程序知道拖放是否真的发生
                    或我们仅仅设置数据 */

  GdkPoint drop_coords;
  gchar *data_type;
  guint32 timestamp;
};

struct _GdkEventDragBegin
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  union {
    struct {
      guint protocol_version:4;
      guint reserved:28;
    } flags;
    glong allflags;
  } u;
};

struct _GdkEventDropEnter
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 requestor;
  union {
    struct {
      guint protocol_version:4;
      guint sendreply:1;
      guint extended_typelist:1;
      guint reserved:26;
    } flags;
    glong allflags;
  } u;
};

struct _GdkEventDropLeave
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 requestor;
  union {
    struct {
      guint protocol_version:4;
      guint reserved:28;
    } flags;
    glong allflags;
  } u;
};

struct _GdkEventDropDataAvailable
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  guint32 requestor;
  union {
    struct {
      guint protocol_version:4;
      guint isdrop:1;
      guint reserved:25;
    } flags;
    glong allflags;
  } u;
  gchar *data_type; /* MIME类型 */
  gulong data_numbytes;
  gpointer data;
  guint32 timestamp;
  GdkPoint coords;
};

struct _GdkEventClient
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  GdkAtom message_type;
  gushort data_format;
  union {
    char b[20];
    short s[10];
    long l[5];
  } data;
};

struct _GdkEventOther
{
  GdkEventType type;
  GdkWindow *window;
  gint8 send_event;
  GdkXEvent *xevent;
};