阅读说明：本技术 窗口关闭方法、装置、电子设备及存储介质 (Window closing method and device, electronic equipment and storage medium ) 是由 胡平 李强 白文吉 张炜 于 2021-09-29 设计创作，主要内容包括：本发明实施例公开了一种窗口关闭方法、装置、电子设备及存储介质。该方法包括：获取当前窗口的关闭触发事件,并广播所述关闭触发事件至候选窗口；判断所述候选窗口中是否存在维护所述当前窗口的窗口信息的目标窗口；若存在,则联动关闭所述当前窗口及所述目标窗口。通过运行本发明实施例所提供的技术方案,可以提高窗口关闭效率和保障用户信息安全。(The embodiment of the invention discloses a window closing method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a closing trigger event of a current window, and broadcasting the closing trigger event to a candidate window; judging whether a target window for maintaining the window information of the current window exists in the candidate windows or not; and if so, closing the current window and the target window in a linkage manner. By operating the technical scheme provided by the embodiment of the invention, the window closing efficiency can be improved and the user information safety can be ensured.)

1. A window closing method, comprising:

acquiring a closing trigger event of a current window, and broadcasting the closing trigger event to a candidate window;

judging whether a target window for maintaining the window information of the current window exists in the candidate windows or not;

and if so, closing the current window and the target window in a linkage manner.

2. The method of claim 1, further comprising, prior to the interlocked closing of the current window and the target window:

acquiring the closing state of the current window, and judging whether the closing state is true;

and if so, executing linkage to close the current window and the target window.

3. The method of claim 1, further comprising:

determining window information maintained by the candidate window according to a preset window association mode of the candidate window; wherein the preset window association mode comprises: at least one of an inheritance window mode and a parent-child window mode.

4. The method according to claim 3, wherein if the preset window association mode of the candidate window is the legacy window mode, determining the window information maintained by the candidate window comprises:

judging whether the candidate window has an open source window or not;

if the window information exists, determining that the window information maintained by the candidate window comprises the window information maintained by the starting source window;

judging whether a new window is started from the candidate window or not;

if so, determining that the window information maintained by the candidate window comprises the window information of the new window.

5. The method according to claim 3, wherein determining the window information maintained by the candidate window if the preset window association mode of the candidate window is the parent-child window mode comprises:

judging whether the candidate window has a parent window or not;

if so, determining that the window information maintained by the candidate window is the window information of the parent window;

judging whether a child window is opened from the candidate window;

and if so, the candidate window does not maintain the window information of the sub-window, and the window information maintained by the sub-window is the window information of the candidate window.

6. The method of claim 1, wherein after the linked closing of the current window and the target window, the method further comprises:

and clearing the user information related to the current window and the target window.

7. A window closing device, comprising:

the broadcasting module is used for acquiring a closing trigger event of a current window and broadcasting the closing trigger event to a candidate window;

the judging module is used for judging whether a target window for maintaining the window information of the current window exists in the candidate windows or not;

and the window closing module is used for closing the current window and the target window in a linkage manner if the judging module judges that the current window and the target window exist.

8. The apparatus of claim 7, wherein the window closing module is further configured to:

and acquiring the closing state of the current window, judging whether the closing state is true, and if so, executing linkage to close the current window and the target window.

9. An electronic device, characterized in that the electronic device comprises:

one or more processors;

a storage device for storing one or more programs,

when executed by the one or more processors, cause the one or more processors to implement the window closing method of any of claims 1-6.

10. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the window closing method according to any one of claims 1 to 6.

Technical Field

The embodiment of the invention relates to the technical field of computers, in particular to a window closing method and device, electronic equipment and a storage medium.

Background

In the case that a user opens multiple pages of a browser through a window or tab, since the opened pages may come from different browser systems and the opening sequence may be different, the pages of the same browser system may be interspersed with the pages of other systems; when a user wants to close pages of the same system, the user can only search and close the pages one by one, and the closing efficiency is reduced. And if the page needing to be closed cannot be closed completely in time, user information can be leaked.

Disclosure of Invention

The embodiment of the invention provides a window closing method and device, electronic equipment and a storage medium, and aims to improve window closing efficiency and guarantee user information safety.

In a first aspect, an embodiment of the present invention provides a window closing method, where the method includes:

acquiring a closing trigger event of a current window, and broadcasting the closing trigger event to a candidate window;

judging whether a target window for maintaining the window information of the current window exists in the candidate windows or not;

and if so, closing the current window and the target window in a linkage manner.

In a second aspect, an embodiment of the present invention further provides a window closing apparatus, where the apparatus includes:

the broadcasting module is used for acquiring a closing trigger event of a current window and broadcasting the closing trigger event to a candidate window;

the judging module is used for judging whether a target window for maintaining the window information of the current window exists in the candidate windows or not;

and the window closing module is used for closing the current window and the target window in a linkage manner if the judging module judges that the current window and the target window exist.

In a third aspect, an embodiment of the present invention further provides an electronic device, where the electronic device includes:

one or more processors;

a storage device for storing one or more programs,

when executed by the one or more processors, cause the one or more processors to implement the window closing method as described above.

In a fourth aspect, the present invention further provides a computer-readable storage medium, on which a computer program is stored, which when executed by a processor implements the window closing method described above.

The embodiment of the invention obtains the closing trigger event of the current window and broadcasts the closing trigger event to the candidate window; the method comprises the steps of closing a current window and a target window which maintains window information of the current window in a linkage mode in the candidate window, confirming whether the candidate window is related to the current window according to the window information whether the current window is maintained when the current window is triggered to be closed, and therefore the target window related to the current window is triggered to be closed together without searching windows related to the current window one by one for closing, and therefore window closing efficiency, linkage closing accuracy and the effect of guaranteeing user information safety are improved.

Drawings

FIG. 1 is a flow chart of a window closing method provided in an embodiment of the present application;

FIG. 2 is a diagram illustrating window information maintained by a window provided in an embodiment of the present application;

FIG. 3 is a diagram illustrating window information maintained by a window provided in an embodiment of the present application;

FIG. 4 is a schematic view of a window closing apparatus according to an embodiment of the present application;

fig. 5 is a schematic structural diagram of an electronic device provided in an embodiment of the present application.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a flowchart of a window closing method provided in an embodiment of the present application, where the present embodiment is applicable to a case of closing a window in a browser, and the method may be executed by a window closing apparatus provided in an embodiment of the present invention, where the apparatus may be implemented by software and/or hardware. Referring to fig. 1, the window closing method provided in this embodiment includes:

step 110, obtaining a closing trigger event of the current window, and broadcasting the closing trigger event to the candidate window.

The closing trigger event is an event triggered when a window closing operation or other operations are performed, the other operations may be a refresh operation, and the like.

When the closing trigger event is monitored to exist, the closing trigger event of the current window triggering the event is obtained and broadcasted to the candidate window, and the closing trigger event carries window information or a current window identifier of the current window. The candidate windows may be all opened windows, or may also be windows having a preset association relationship with the current window, which is not limited in this embodiment.

In an embodiment, the close trigger event may be broadcasted to the candidate window through a message mechanism such as websocket and broadcastChannel, which is not limited in this embodiment.

And step 120, judging whether a target window for maintaining the window information of the current window exists in the candidate windows.

And maintaining window information of the window, namely monitoring the window, and performing corresponding operation according to the event generated by the window. And if the candidate window maintains the window information of the current window, the candidate window is considered to be associated with the current window. And judging whether a target window for maintaining the window information of the current window exists in the candidate windows, namely judging whether a window related to the current window exists in the candidate windows receiving the closing trigger event. Illustratively, the candidate windows include A, B and C, the current window is Q, window A maintains information of window B, window B maintains information of window C, and window C maintains information of window Q, then window C is the target window.

The content of the window information maintained by each window can be predetermined or updated according to the change of the window state. For example, the window C maintains the information of the window Q, and if the window K is opened from the window C, the window information of the window K may be added to the window information maintained by the window C.

And if the target window exists, the target window performs corresponding subsequent processing after acquiring the closing trigger event of the current window through broadcasting. If other windows except the target window exist in the candidate windows, the other windows can only acquire the closing trigger event, and do not perform subsequent processing.

And step 130, if the current window and the target window exist, closing the current window and the target window in a linkage manner.

And if the target window exists, closing the target window and the current window together.

In this embodiment, optionally, before the linkage closing of the current window and the target window, the method further includes:

acquiring the closing state of the current window, and judging whether the closing state is true;

and if so, executing linkage to close the current window and the target window.

And after the target window receives a closing trigger event, detecting the closing state of the current window so as to determine whether to close the target window according to the closing state. The closed state of the window may be determined by the closed state of the window, which is not limited in this embodiment.

If the closing state is true, the current window is indicated to be closed indeed, and then the subsequent operation of closing the current window and the target window in linkage is executed. And if the closing state is false, keeping the current state of the target window.

The method and the device avoid that the associated window is directly closed after the closing trigger event of the current window is detected, and the closing trigger event of the current window is possibly triggered by the user through operations such as refreshing the current window, so that the target window associated with the current window is closed by mistake, and the accuracy of linkage closing of the window is improved.

In this embodiment, optionally, after the current window and the target window are closed in a linkage manner, the method further includes:

and clearing the user information associated with the current window and the target window.

After the current window and the target window are closed, triggering a corresponding security mechanism to notify the server and locally clear user information such as session, webstore, cookie, and the like associated with the target window, which is not limited in this embodiment. Thereby guaranteeing the information security of the user.

According to the technical scheme provided by the embodiment, when the current window generates the closing trigger event, the target window having the association relation with the current window can be accurately determined according to whether the window information of the current window is maintained, and the target window and the current window are closed in a linkage manner, so that the window closing efficiency and the linkage closing accuracy are improved, and the effect of guaranteeing the user information safety is achieved.

The method comprises the steps of performing supplementary explanation on window information maintained by a candidate window, and compared with the scheme, the scheme is specifically optimized in that the window information maintained by the candidate window is determined according to a preset window association mode of the candidate window; wherein the preset window association mode comprises: at least one of an inheritance window mode and a parent-child window mode.

The preset window association mode refers to a preset association mode of window information maintained by the candidate window. An inherited window mode refers to window information maintained by a candidate window being associated with window information maintained by other windows. Parent-child window mode refers to the candidate window maintaining window information associated with the parent window and/or child window of the candidate window.

In a specific embodiment, if the preset window association mode of the candidate window is the inheritance window mode, determining window information maintained by the candidate window includes:

judging whether the candidate window has an open source window or not;

if the window information exists, determining that the window information maintained by the candidate window comprises the window information maintained by the starting source window;

judging whether a new window is started from the candidate window or not;

if so, determining that the window information maintained by the candidate window comprises the window information of the new window.

Specifically, in which the open source window of the candidate window is the window required for opening the candidate window, for example, the candidate window C1 is opened from the window C, and then the window C is the open source window of the window a 1.

When the preset window association mode of the candidate window is the inheritance window mode, and when the starting source window exists, the window information maintained by the candidate window may include all window information maintained by the starting source window and the candidate window itself. For example, the window information maintained by the open source window C includes the window a, the window B, and the open source window C itself, and the window information maintained by the candidate window may include the window a, the window B, the open source window C, and the candidate window C1 itself. Further, if a new window is opened from the candidate window, for example, the new window C2 is opened from the candidate window C1, it is determined that the window information maintained by the candidate window includes the window information of the new window C2, that is, the window information of the new window C2 may be newly added to the window information originally maintained by the candidate window C1, that is, after the new window C2 is opened by the candidate window C1, the window information currently maintained by the candidate window may include the window a, the window B, the opening source window C, the candidate window C1 itself, and the window C2. All window information maintained by a window may be referred to as a dynamic link corresponding to the window, for example, the dynamic links of the candidate window C1 are window a, window B, window C1, and window C2. Windows in the same dynamic link can be closed in a linked manner, that is, closing a window in the same dynamic link triggers closing all windows in the dynamic link.

For example, fig. 2 is a schematic diagram of window information maintained by a window provided in an embodiment of the present application. As shown in fig. 2, the specific implementation logic for establishing the maintenance relationship of the window information of each window based on the inheritance window mode and triggering the closing of the target window based on the maintenance relationship is as follows:

a user logs in the browser system through the login screen, and the login screen after successful login is converted into a homepage window. The login manner may be, but is not limited to, account secret login, Ukey login, and face login, which is not limited in this embodiment.

And opening one or more main windows such as a business screen window and a map screen window in the main window. The homepage window synchronizes the created window information to the business screen window and the map screen window, and the business screen and the map maintain respective window information. The maintained window information of the map screen window, the home page window and the business screen window can be the home page window, the map screen window and the business screen window. When any one of the local screen window, the home page window and the business screen window is actually closed, the other windows are closed in a related way.

And if the business screen window is closed, triggering the beforunload closing trigger event, and broadcasting the closing trigger event. After receiving the closing event, the map screen window and the home page window are not closed immediately, but are judged whether the closing state of the business screen window is closed, so that beforeunload caused by refreshing is realized, and window closing operation cannot be caused.

And opening a new window C in the service screen window, opening a new window C1 in the window C, and opening a window information new window C maintained by the service screen window and a window information new window C1 maintained by the window C. And updating the maintained window information of the business screen window into a home page window, a map screen window, a business screen window and a window C, and updating the maintained window information of the window C into the home page window, the map screen window, the business screen window, the window C and the window C1. The state of window C is maintained and detected by the service screen window and the state of window C is maintained and detected by window C1. Window C1 includes window information maintained by window C, including the home window, the map screen window, the business screen window, window C, and window C1 themselves.

Once window C1 is closed, a close trigger event is broadcast to the business screen window, map screen window and window C, etc., but since window C maintains window information including window C1, the close trigger event for window C1 results in the closing of window C, which in turn results in the closing of the business screen window. Similarly, the window information maintained by the map screen window and the home page window comprises the business screen, and when the business screen is closed, the map screen window and the home page window are both closed.

In the foregoing specific embodiment, in the inheritance window mode, the candidate windows maintain window information for opening the source window, and window information of the new window, and respectively establish window information maintained corresponding to each candidate window, that is, respectively establish dynamic link information corresponding to each candidate window, so that when a window closing event is monitored, a target dynamic link corresponding to a current window can be determined according to the window information of the current window triggering the window closing event and the dynamic link information corresponding to each candidate window, and all windows in the target dynamic link are closed in a linked manner, thereby improving window closing efficiency and the comprehensiveness of linked closing.

In another specific embodiment, if the preset window association mode of the candidate window is the parent-child window mode, determining window information maintained by the candidate window includes:

judging whether the candidate window has a parent window or not;

if so, determining that the window information maintained by the candidate window is the window information of the parent window;

judging whether a child window is opened from the candidate window;

and if so, the candidate window does not maintain the window information of the sub-window, and the window information maintained by the sub-window is the window information of the candidate window.

Specifically, in parent-child window mode, the window information maintained by the candidate window is relevant only to its parent window. Illustratively, if candidate window A1 is a child of parent window A, i.e., window A1 is opened from parent window A, then window A1 maintains window information that is the window information of parent window A. If the child window A2 is opened from window A1, window A1 does not maintain the window information for its child window A2, and the child window A2 only maintains the window information for its parent window A1, but does not maintain the window A information. All window information maintained by a window may be referred to as a dynamic link corresponding to the window, for example, the dynamic link of the candidate window a1 is window a, and the dynamic link of the sub-window a2 is window a 1. Windows in the same dynamic link can be closed in a linked manner, that is, closing a window in the same dynamic link triggers closing all windows in the dynamic link.

In a specific embodiment, fig. 3 is a schematic diagram of window information maintained by a window provided in an embodiment of the present application. As shown in fig. 3, the logic for establishing the maintenance relationship of the window information of each window based on the parent-child window mode and triggering the closing of the target window based on the maintenance relationship is as follows:

a user logs in the browser system through the login screen, and the login screen after successful login is converted into a homepage window.

And opening one or more main windows such as a business screen window and a map screen window in the main window. The homepage window synchronizes the created window information to the business screen window and the map screen window, the business screen and the map screen maintain respective window information, and the maintained window information of the map screen window, the homepage window and the map screen window can be the homepage window, the map screen window and the business screen window because the homepage window, the business screen window and the map screen window are not in a parent-child window relationship. When any one of the local screen window, the home page window and the business screen window is actually closed, the other windows are closed in a related way.

And if the business screen window is closed, triggering the beforunload closing trigger event, and broadcasting the closing trigger event. After receiving the closing event, the map screen window and the home page window are not closed immediately, but whether the closing state of the business screen window is closed or not is judged, so that beforeunload caused by refreshing is avoided, and window closing operation is not caused.

Further, a child window C is opened in the service screen window, a child window C1 is opened in the window C, because the child window C and the service screen are in a parent-child window relationship, and the child window C1 and the child window C are in a parent-child window relationship, based on the parent-child window mode, the child window only maintains the window information of the parent window, and the parent window does not maintain the window information of the child window, the window information maintained by the child window C is the window information of the service screen window, and the window information maintained by the child window C1 is the window information of the child window C.

Once the sub-window C is closed, a closing event is broadcasted to all candidate windows, and because only the sub-window C1 maintains the window information of the sub-window C, only the sub-window C1 is closed in a linkage manner, and other windows do not maintain the window information of the sub-window C and the sub-window C1, the closing of the sub-window C and the sub-window C1 does not cause any influence on other windows, so that the effect of closing the sub-window C without influencing other windows can be achieved; that is, the closing of the child window does not affect the closing of the parent window and the main window, and the control logic of the main window and the child window is optimized.

In the specific embodiment, by distinguishing the window information maintained by the parent window and the child window, the parent window does not maintain the window information of the child window, and the child window only maintains the window information of the parent window, so that the parent window is not affected when the child window is closed, the closing of the parent window can trigger the closing of the child window, the window closing efficiency and the pertinence of linkage closing are improved, and the window closing requirements under certain service scenes are met.

The embodiment of the invention determines the window information maintained by the candidate window through the preset window association mode of the candidate window, determines different window information maintained by the candidate window according to different service requirements, and is convenient for accurately determining the target window when the window is closed in the follow-up process so as to improve the accuracy and pertinence of linkage closing of the window.

It should be noted that other association modes can be established according to other specific service requirements to determine window information maintained by each window, and a target window closed in a linkage manner is determined by judging whether to maintain window information of a current window triggering a closing triggering event, so that different target windows are triggered to be closed by maintaining different window information, and requirements of various service scenes are met; if the marks of some windows can be set as special marks, and when the maintenance relation of the window information is established, the window information of the window with the special mark is maintained by the appointed window according to the preset rule, so that the appointed window is closed in a linkage manner when the window with the special mark triggers a closing triggering event. The method and the device do not limit how the maintenance information of each window is set, and under the concept of the method and the device, the maintenance information of each window is set and the linkage closing of the window is triggered according to the maintenance information.

Fig. 4 is a schematic structural diagram of a window closing device provided in an embodiment of the present application. The device can be realized in a hardware and/or software mode, can execute the window closing method provided by any embodiment of the invention, and has corresponding functional modules and beneficial effects of the execution method. As shown in fig. 4, the apparatus includes:

a broadcasting module 410, configured to obtain a closing trigger event of a current window, and broadcast the closing trigger event to a candidate window;

a determining module 420, configured to determine whether a target window for maintaining the window information of the current window exists in the candidate windows;

and a window closing module 430, configured to close the current window and the target window in a linked manner if the determining module determines that the current window and the target window exist.

According to the technical scheme provided by the embodiment, when the current window generates the closing trigger event, the target window having the association relation with the current window can be accurately determined according to whether the window information of the current window is maintained, and the target window and the current window are closed in a linkage manner, so that the window closing efficiency and the linkage closing accuracy are improved, and the effect of guaranteeing the user information safety is achieved.

On the basis of the above technical solutions, optionally, the window closing module is further configured to:

and acquiring the closing state of the current window, judging whether the closing state is true, and if so, executing linkage to close the current window and the target window.

On the basis of the above technical solutions, optionally, the apparatus further includes:

the information maintenance determining module is used for determining window information maintained by the candidate window according to a preset window association mode of the candidate window; wherein the preset window association mode comprises: at least one of an inheritance window mode and a parent-child window mode.

On the basis of the above technical solutions, optionally, if the preset window association mode of the candidate window is the inheritance window mode, the information maintenance determining module includes:

a starting source window existence judging unit, configured to judge whether a starting source window exists in the candidate window;

a first information maintenance determining unit, configured to determine that the window information maintained by the candidate window includes the window information maintained by the source window if the source window presence determining unit determines that the window exists;

a new window opening judging unit, configured to judge whether to open a new window from the candidate window;

and the second information maintenance determining unit is used for determining that the window information maintained by the candidate window comprises the window information of the new window if the new window opening judging unit judges that the window information maintained by the candidate window comprises the window information of the new window.

On the basis of the foregoing technical solutions, optionally, if the preset window association mode of the candidate window is the parent-child window mode, the information maintenance determining module includes:

a parent window existence judging unit, configured to judge whether the candidate window has a parent window;

a third information maintenance determining unit, configured to determine that the window information maintained by the candidate window is the window information of the parent window if the parent window existence determining unit determines that the parent window exists;

a sub-window opening judging unit, configured to judge whether to open a sub-window from the candidate window;

and the fourth information maintenance determining unit is used for not maintaining the window information of the sub-window by the candidate window if the judgment of the sub-window opening judging unit is yes, and the window information maintained by the sub-window is the window information of the candidate window.

On the basis of the above technical solutions, optionally, the apparatus further includes:

and the user information clearing module is used for clearing the user information related to the current window and the target window after the window closing module.

Fig. 5 is a schematic structural diagram of an electronic device provided in an embodiment of the present application, and as shown in fig. 5, the electronic device includes a processor 50, a memory 51, an input device 52, and an output device 53; the number of the processors 50 in the electronic device may be one or more, and one processor 50 is taken as an example in fig. 5; the processor 50, the memory 51, the input device 52 and the output device 53 in the electronic apparatus may be connected by a bus or other means, and the bus connection is exemplified in fig. 5.

The memory 51 is a computer-readable storage medium, and can be used for storing software programs, computer-executable programs, and modules, such as program instructions/modules corresponding to the window closing method in the embodiment of the present invention. The processor 50 executes various functional applications and data processing of the electronic device by executing software programs, instructions and modules stored in the memory 51, that is, implements the window closing method described above.

The memory 51 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required for at least one function; the storage data area may store data created according to the use of the terminal, and the like. Further, the memory 51 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some examples, the memory 51 may further include memory located remotely from the processor 50, which may be connected to the electronic device through a network. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

Embodiments of the present invention also provide a storage medium containing computer-executable instructions, which when executed by a computer processor, perform a window closing method, the method comprising:

acquiring a closing trigger event of a current window, and broadcasting the closing trigger event to a candidate window;

judging whether a target window for maintaining the window information of the current window exists in the candidate windows or not;

and if so, closing the current window and the target window in a linkage manner.

Of course, the storage medium provided by the embodiment of the present invention contains computer-executable instructions, and the computer-executable instructions are not limited to the operations of the method described above, and may also perform related operations in the window closing method provided by any embodiment of the present invention.

From the above description of the embodiments, it is obvious for those skilled in the art that the present invention can be implemented by software and necessary general hardware, and certainly, can also be implemented by hardware, but the former is a better embodiment in many cases. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as a floppy disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a FLASH Memory (FLASH), a hard disk or an optical disk of a computer, and includes several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute the methods according to the embodiments of the present invention.

It should be noted that, in the embodiment of the window closing apparatus, the included units and modules are only divided according to functional logic, but are not limited to the above division as long as the corresponding functions can be implemented; in addition, specific names of the functional units are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present invention.

It is to be noted that the foregoing is only illustrative of the preferred embodiments of the present invention and the technical principles employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail by the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the present invention, and the scope of the present invention is determined by the scope of the appended claims.