METHOD AND APPARATUS TO DISPLAY OBJECTS USING WINDOWS
Field of Invention This invention relates to computer user interfaces, and more specifically to user interfaces which display information using windows.
Background of the Invention Many conventional computer software applications display information to a user on a display screen such as a conventional computer display. When a graphical user interface is used to display information, an element of the information may be displayed as an object on the screen. Referring now to Figure IA, many objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 are shown.
Many conventional computer software applications utilize a user interface known as a window. The window is used as a portal to the information displayed by the computer software application, and at any time may allow for the display of a subset of the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 which represent the information the software application is capable of displaying. The user is able to navigate among large amounts of information easily, because the user is only required to relate to the portion of the information that is displayed in the window at any time. Referring now to Figure IB, the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 of Figure IA are shown, with some of the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, enclosed in a window 160 displayed on a display screen 172. The window 160 shown in Figure IB is a rectangle that has an upper border 162, a left border 164, a right border 166 and a lower or bottom border 168 although other shapes of the window 160 are possible using any number of borders.
A user of the application program sees only the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, representing the information that are within the borders 162, 164, 166, 168 of, or inside, the window 160. In a conventional application program, the remaining objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 are not seen at all by the user, although they are shown in Figure IB as an aid in understanding. In
many conventional computer software applications, only the information represented by the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118 that are in the window 160 may be accessed and manipulated by the user.
In order to display, manipulate or access the objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 outside the window 160, the user manipulates the window 160, using a pointing device such as a mouse type controller which controls a pointer 170, or using a keyboard in conventional software applications, to position the window 160 over some or all of the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 desired.
As the user positions the window 160 over such desired objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158, the window 160 does not change position relative to the computer display screen 172 in many conventional application programs. Instead, the display of the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 that are visible in the window 160 is adjusted as if the window 160 had changed its position. For example, to see and manipulate the objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 to the right of the window 160, the user would indicate that the window 160 was to move right, but the window 160 would remain in the same position relative to the computer display screen 172. However, the information 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 would scroll into position within the window 160 and the information 100, 102, 104, 106, 108, 110, 112, 114, 116, 118 that was formerly in the window would scroll to the left until it is no longer displayed in the window 160 to simulate the window 160 moving right. During this simulated movement, the relative spacing between the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 remains the same, although some objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118 scroll out of view and other objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 appear.
In the above example, the user is required to know the arrangement of the objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 representing desired information relative to the position of the window 160. That is, the user was required to know that objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 were to the right of the original position of the window 160 even though those objects were not visible.
Some information lends itself to this knowledge, such as information arranged in a known order. For example, the user of a word processing program may have an idea that the forty fourth chapter of a manuscript is above the forty fifth chapter, and thus, may be able to manipulate the window 160 to locate the desired information. However, where the position of the desired information relative to the information displayed in the window 160 is not readily apparent, it is difficult for the user to locate the desired information by manipulating the window 160. For example, the information may not have an inherent "order" which can be used by the application program to arrange the information in a fashion that would be apparent to the user, or the current position of the window 160 with respect to the desired information may not be readily apparent. To again use the example of the word processing program, it may not be clear to the user of the word processing program which chapter is currently being displayed by the window 160, so the user may not know whether the desired forty fifth chapter is up or down from the text currently displayed in the window 160.
Many computer software applications allow the user to compensate for the lack of knowledge of relative positions of the objects displayed in the window 160 to the positions of the desired objects by allowing the user to zoom in and out, causing more objects to appear on the screen, though smaller in size, as if the window had moved in the z-axis, either closer to the objects or farther away from them. However, in order to see both the objects originally displayed in the window as well as the desired objects, the objects may have to be displayed in a size too small to identify them. Additionally, some graphical user interfaces display data in three dimensions, allowing the user to navigate past objects in three dimensions like astronauts navigating a spaceship among stars. To provide the three- dimensional look, objects that are a certain distance away from the user in the direction of the z-axis into the screen are not displayed in the same way that distant stars are not visible to the naked eye. Thus zooming out sufficiently in order to see more objects may cause the desired objects to cease to be displayed by the graphical user interface, eliminating the utility of the zoom in /zoom out capability to help identify the direction of desired objects.
Maneuvering through objects displayed in a three-dimensional graphical user interface is also made difficult when the objects are arranged in a hierarchy. Using a two-dimensional graphical user interface, hierarchical arrangements of objects, such as people in an organization chart, may be shown using lines and positions on the screen. Objects in each level of the
hierarchy occupy certain areas of the screen to show the level in the hierarchy of the objects, and lines may be drawn to show hierarchical relationships such as parent/child, sibling/sibling, etc. However, lines showing the relationships in a three dimensional user interface would overly clutter the interface making it more difficult to navigate among the objects, and positions are harder to ascertain due to parallax effects.
Summary of Invention In accordance with the present invention, methods, apparati and computer program products display at or near the border of a window certain objects which have an original position outside the window, and thus, would otherwise not be displayed. Objects so displayed at or near the border of the window are displayed at a position representing the direction of their original position, allowing a user to navigate towards the original position of a desired object by navigating the window toward the displayed position of the object at or near the border of the window. When the window is navigated so as to contain the original position of the desired object, the desired object is displayed away from the border of the window in a conventional manner. Thus, the present invention allows objects which are in the window to be displayed in a manner similar to those displayed by a conventional window, while providing the user an indication of the direction of objects which would not otherwise be visible in the window and therefore not be displayed in a conventional user interface. In addition, hierarchical arrangements of objects may be shown using colors to distinguish the level of each object in the hierarchy, eliminating the need to show relationships using two-dimensional positions of the objects and lines between the objects.
Brief Description of the Drawings Figure IA is a block diagram of a number of objects representing elements of information arranged in space by a conventional application program.
Figure IB is a block diagram of the display of objects in a conventional application program in which the objects of Figure IA which are located inside a window of a display screen are displayed, and objects not located inside the window are not displayed.
Figure 2A is a block diagram of the display of the objects of Figure IA in a window by an application program according to one embodiment of the present invention.
Figure 2B is a block diagram of the display of the objects of Figure 2A displayed in the window of Figure 2A shifted down according to one embodiment of the present invention.
Figure 2C is a block diagram of the objects of Figure 2A displayed in the window of Figure 2A shifted left according to one embodiment of the present invention.
Figure 3A is a flowchart illustrating a method of displaying objects according to one embodiment of the present invention.
Figure 3B is a flowchart illustrating the display of an object according to the level of the object in a hierarchy according to one embodiment of the present invention.
Figure 4 is a block schematic diagram of an apparatus for displaying objects using a window according to one embodiment of the present invention. Figure 5 A is a block schematic diagram of a position adjuster shown in
Figure 4 according to one embodiment of the present invention.
Figure 5B is a block schematic diagram of the compare shown in Figure 5A according to one embodiment of the present invention.
Figure 5C is a block schematic diagram of the adjuster shown in Figure 5A according to one embodiment of the present invention.
Figure 5D is a block schematic diagram of a computational unit of Figure 5C according to one embodiment of the present invention.
Figure 5E is a block schematic diagram of an apparatus for providing a color of an object according to the level in a hierarchy of the object according to one embodiment of the present invention.
Figure 6 is a block schematic diagram of a conventional computer system and a computer program product.
Detailed Description of a Preferred Embodiment The present invention may be used to display objects in various dimensions. Objects are used to display information such as application program data, files, or other information, and may be displayed as a box or other simple shape, an icon such as a file folder, or a complete set of images displayed in a sequence to simulate a motion picture. Many conventional application programs can display information using two dimensions, in which all of the objects displayed are located on the same plane approximately parallel with the plane of the computer screen 172. Other conventional application
programs display information in three dimensions, allowing some objects to be displayed in a manner that represents multiple planes.
The present invention may be used to display information organized in many types of arrangements. One type of arrangement of information that may be displayed using the present invention is a hierarchical arrangement. In such an arrangement, each object is arranged in one of several levels, and may be related to objects at other levels. Objects related to an object on a higher level are said to "descend" from the object on the higher level. The object at the higher level from which an object descends is said to be the "parent" of the object. The family nomenclature is carried out in various ways, with objects sharing the same parent described as "siblings," and the parent of the parent of an object said to be the object's "grandparent." Any object which descends from another object, no matter how many levels removed, is said to be a "descendant" of the object. Hierarchical arrangements of data lend themselves to a three dimensional display. Referring again to Figure IA, objects 100, 110, 120, 130, 140, 150 represent objects on the same level, and objects 102, 104, 106, 108 are the child objects of object 100, objects 112, 114, 116, 118 are the child objects of object 110, objects 122, 124, 126, 128 are the child objects of object 120, objects 132, 134, 136, 138 are the child objects of object 130, objects 142, 144, 146, 148 are the child objects of object 140, and objects 152, 154, 156, 158 are the child objects of object 150. In one embodiment, each object 102, 104, 106, 108, 112, 114, 116, 118, 122, 124, 126, 128, 132, 134, 136, 138, 142, 144, 146, 148, 152, 154, 156, 158 on the child level is displayed differently from the objects 110, 120, 130, 140, 150 on the parent level. The differences between display of objects at different levels may be in one or more of color, size or display intensity of either the object or a portion of the object such as a border of the object. Displaying objects in a different size can provide the illusion of a three dimensional display where objects of each level are displayed on a different plane. For example, child objects 102, 104, 106, 108, 112, 114, 116, 118, 122, 124, 126, 128, 132, 134, 136, 138,
142, 144, 146, 148, 152, 154, 156, 158 appear to be displayed in a plane behind the plane containing their respective parent objects 100, 110, 120, 130, 140, 150. As the user navigates towards the objects 100 102, 104, 106, 108, 112, 114, 116, 118, 122, 124, 126, 128, 132, 134, 136, 138, 142, 144, 146, 148, 152, 154, 156, 158 they grow in size until a plane is passed, at which time the objects in the passed plane disappear. As the user navigates away from the objects 100, 102, 104, 106, 108, 112, 114, 116, 118, 122, 124, 126, 128, 132, 134, 136, 138, 142, 144, 146, 148, 152, 154, 156, 158, they shrink, and as the user backs past a plane, objects appear.
In one embodiment, only the objects in a user-configurable number of planes may be displayed. As the user navigates forward in the z-axis past one plane, the objects in the plane that was passed are no longer displayed, and objects in a plane further back are displayed. The process works in reverse as the user navigates backward. Thus, objects in a user-configurable number of planes in "front" of the user are always displayed.
In one embodiment, hierarchically arranged objects are displayed in three dimensions as described above, although the present invention applies to the display of any type of arrangement of objects in two or more dimensions. Referring now to Figure 2, the objects of Figure IB displayed according to one embodiment of the present invention are shown. Some of the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118 that would be displayed in the window 160 using conventional display methods are displayed so as to appear as if they were displayed in a conventional fashion. However, other objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 that would otherwise not be displayed using conventional methods because they would be located in a position outside the borders 162, 164, 166, 168 of the window 160 are displayed in an outer portion 161 inside the window 160 that is at or near the border 162, 164, 166, 168 nearest the original position of object as shown in Figure IB. Because the objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 are visible within the window 160 in a manner which shows their direction, a user may more easily navigate the display toward such objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158. As the position of the window 160 is navigated relative to the objects
100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 representing the data, in one embodiment, the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 are repositioned within the window 160 as described above. For example, if the user moved the window down slightly, all of the objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 would appear to move up relative to the window 160 to reflect their new position relative to the window 160. Thus, as shown in Figure 2B, objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 that would otherwise not be displayed using conventional methods may slide along the borders 162, 164, 166, 168, or
even move adjacent to another border 162, 164, 166, 168 depending on their position relative to the window 160.
In some display instances, objects will bunch up around the edges which causes conflicts for space in the outer portion 161 of the window 160. Referring now to Figure 2C, a window 160 moved such that the leftmost objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138 are near the center of the window 160, and the remaining objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 are in the outer portion 161 of the window 160 near the right border 166 to indicate their original position to the right of the centered objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138. In one embodiment, certain objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118 that are closer to the objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138 that are displayed away from the borders 162, 164, 166, 168 of the window 160 are displayed "over" objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 that are further away from such objects 120, 122, 124, 126, 128, 130, 132, 134, 136, 138, causing objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 not to be displayed, as they are not displayed in the Figure. In other embodiments, the set of objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 are moved slightly up or down to take available space, such as the space between objects 106 and 112 and the space above object 102. In other embodiments, the "nearer" objects 100, 102, 104, 106, 108, 110, 112, 114, 116, 118 are moved slightly toward the center of the window 160 with portions of the underlying objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158 remaining visible so as to indicate the presence of these objects 140, 142, 144, 146, 148, 150, 152, 154, 156, 158. In a three dimensional display, objects at higher levels are always displayed over objects at lower levels, with conflicting objects on the same level being displayed as described above.
Referring now to Figure 3A, a method of displaying objects according to one embodiment of the present invention is shown. An object capable of display is selected 310. In one embodiment, the object is examined to determine whether to display the object 312. In one embodiment, any object capable of display is displayed and so step 312 is not performed. In another embodiment, only objects at a certain level or levels of a hierarchy are displayed. This selection process can act as a filter in a hierarchical arrangement of objects where displaying all objects capable of being displayed would overly clutter the display. In one embodiment, the number of levels of objects to be displayed is user selectable and the objects selected for display are that number of objects in "front" of the user as described above. Referring
momentarily to Figure 2, only objects on two levels are displayed, with objects on other levels not displayed.
If the object selected is to be displayed, it is examined to determine whether its present position is within the borders of the window 318. In one embodiment, each object and contains a position identifier which describes its position. The position identifier uses a two - coordinate pair system such as a pixel coordinate system having an x and a y coordinate describing the number of pixels from the upper left corner of the universe of objects, with (0,0) representing the upper leftmost pixel. Referring momentarily to Figure IA, the upper left hand corner of the object 122 would represent (0,0). The position identifier may be the two coordinate pairs identifying two diagonal corners of the smallest rectangle into which the object will fit where objects have different sizes, or any other position identifier which allows the outer boundary of each object to be identified or computed. Referring momentarily to Figure IB, in one embodiment, the window 160 is a rectangle, the borders 162, 164, 166, 168 of the window 160 may be described in the same fashion using the same coordinate system. An object may be identified as inside or outside the borders of the window 160 by comparing the four coordinates of the outer edge of the object with the corresponding coordinates of the borders 162, 164, 166, 168 of the window 160 according to its current size and position. For example, if the leftmost coordinate and rightmost coordinate of the objects are both between the left and right borders 164, 166 of the window 160, and the top and bottom coordinates of the object are similarly between the top and bottom borders 162, 168 of the window 160, the object is fully within the borders 162, 164, 166, 168 of the window 160. Otherwise, the object is at least partially outside the borders 162, 164, 166, 168 of the window 160.
Referring again to Figure 3A, if the object is determined to be inside the window, it is displayed in a conventional fashion 322, for example by copying the object to an offscreen buffer which is then rendered by the display drivers and sent to a display via a display interface. If there are more objects to be displayed 324, another object is selected 326 and the method repeats at step 312 as shown in the figure. If there are no more objects to be displayed, the method terminates 328.
In one embodiment, the each of the available objects repeatedly cycle through the method so there are always "more" objects until the window is minimized or closed and so the termination step 328 is never executed until the window is minimized or closed.
In the event that an object is not inside the window at step 318, certain display characteristics, such as the position of the object, are first adjusted 320 for example to reposition the object within the window for display. In one embodiment, this adjustment is made only to the position of the object to allow the object to be displayed in its original size and shape within the window. In such embodiment, the one or two coordinates of the object outside the borders of the window are substituted with the corresponding coordinate of the window. The coordinate of the object representing the opposite side from the side adjusted is adjusted by the same amount so as to preserve the original size of the object.
This type of adjustment step 320 results in a position of the object that is inside the window, near the border of the window and nement is made only to the position of the object to all results in a position results in a position of the object that is inside the window, near the border of the results in a position results in r results in a position of the object that is inside the window re results in a position of the object that is inside results in a position results in a position of the object that is ins re results in a position of results in a position o results in a position of the object that is in re results in a position of the object that is inside the window, near the border of the window and nement is re results in a position of the object that results in a position o results in a position of the object that is inside the window re results in results in a position of the object that is inside the window, near the r results in results results i results in a position of the object that is inside the window, near the border of the window and nement is made only to the position of the objec results in a posi results in a position of the object that is inside the window, near the border of the window and nement is made only to the position of the object to all2. The coordinates of each object displayed is stored in a table in order to assist in the determination. In another embodiment, such blocked objects 132 may be displayed slightly overlapped with, or adjacent to, the objects blocking them, for example by adjusting overlapping objects further toward the center of the window 160, with the objects with original positions furthest from the window 160 positioned nearest the borders 162, 164, 166, 168 . In such embodiments, the positions of other objects already in the window may be stored in a table and the location of the object being located is checked against the objects in the table to see if the overlap that would result is acceptable, and if not, further adjustments must be made. In one embodiment, objects are adjusted in the order of their original positions relative to the center of the window 160 to provide a consistent conflict resolution.
In another embodiment, the adjustment is made to the position as well as the size or shape to allow the object to fit partially within the window 160, the remaining portion either being displayed outside the window or not displayed at all. In another embodiment, an adjusted object that is smaller in one or more dimensions than corresponding maximum measurements displayed in its original size and shape is displayed in its full size and original shape within the window, while adjusted objects larger than the maximum measurements are displayed within the window in a different size or shape that does not exceed the maximum measurement or displayed in its original size and shape with a portion of the object in the window and a portion displayed outside the window so that the object appears to "overlap" the border of the window.
Referring momentarily to Figure 2, objects 122, 124, 126, 128, 132, 134, 136, 138 are smaller in a side to side dimension than maximum measurement 180 and are therefore fully displayed within the window 160, but objects 120, 130 are wider than maximum dimension 180 and are therefore only partially displayed within the window, with portions 121, 131 either displayed outside the window or not displayed.
Referring again to Figure 3A, in one embodiment, the adjustment step 320 is performed in a manner that does not erase the original characteristics of the object, allowing the characteristics such as the position of the objects to be retrieved and processed at a later time based on their original positions prior to adjustment step 320. In one embodiment, each object contains its original characteristics and its adjusted characteristics, so that the original characteristics are not lost after adjustment 320. In another embodiment, the adjusted characteristics are not stored with the object, but immediately used to display the object, so that the original characteristics are unaffected. In another embodiment, the method of Figure 3A operates on a copy of the object, preserving the original characteristics of the object for use in subsequent execution of the method shown in Figure 3A.
Other characteristics besides the location, size and shape of the objects that are adjusted 320 to fit within the window may be adjusted so as to distinguish between objects which are displayed in the "outer locations" of the window, that is, inside the window near the borders of the window, before adjustment from those which are displayed in the outer locations of the window after adjustment. In one embodiment, such objects are displayed at a different display intensity, e.g. more dimly, than objects having positions that
are not adjusted. In another embodiment, objects that have been adjusted are displayed in a color that is different from objects that are not adjusted.
Where objects have a hierarchical arrangement, the display step 322 may involve displaying the object according to the objects level in the hierarchy. Referring now to Figure 3B, a method of displaying an object according to the level of the object in the hierarchy according to one embodiment of the present invention is shown. The level of the object within the hierarchy is identified 330. In one embodiment, each object contains its own level, allowing it to be identified by querying the object. The display color of objects at that level in the hierarchy is looked up 332, for example by using a table look up of user selectable colors for each level in the hierarchy. In one embodiment, objects at only a few levels of the hierarchy are displayed at any one time, allowing the colors used for each level to be reused for other levels in the hierarchy. For example, the look up table may specify that objects at level one use blue, objects at level two use green and objects at level three use red. If there are more than three objects, the color selected is the level of the object in the hierarchy modulus three, meaning objects at level four use blue, and so on. The object may then be rendered in the color corresponding to its level in the hierarchy 333. Referring now to Figure 4, an apparatus 400 for displaying objects according to one embodiment of the present invention is shown. Objects are stored in an addressable object storage device 410 such as a memory or a hard disk. In one embodiment, objects include a set of characteristics such as coordinate pairs describing the position of the object, and may include other display characteristics such as color, size, shape and intensity as well. In one embodiment, some of the characteristics are calculated only for the levels currently visible. The object output 412 of storage device 410 is coupled to the input 414 of retriever 416. Retriever 416 retrieves one or more objects from the object storage 410 using address lines 408 to identify the objects to be retrieved from storage device 410. Retriever 416 may retrieve each of the objects once until the prompted to repeat the retrieval cycle based on a signal received at optional input 418 coupled to output of processor 450 which signals that the cycle is to be repeated because, for example, the window in which the objects are to be displayed has been moved relative to the objects or resized. Alternately, retriever 416 may periodically re-retrieve each of the objects in object storage 410 so that objects are retrieved and processed as described herein in an endless cycle. The output 420 of the retriever 416 is coupled to the input 422 of optional display filter 424. Optional display filter 424 identifies whether
the object or objects retrieved by retriever 416 are to be displayed according to criteria received by display filter input 426 from output of processor 450. In one embodiment, each object contains its level in a hierarchy as described above, and one or more criteria indicators corresponding to the levels corresponding to objects which are to be displayed are accepted by filter input 426. Display filter 424 passes objects that meet the criteria to be displayed to its output 428, but does not pass objects which are not to be displayed.
Position adjuster 432 has an input 430 coupled to output 428 of display filter 424 and identifies whether the object or objects it receives at its input 430 are within the borders of the window, which are identified by coordinates or other position identifiers received at window coordinate input 434 from output of processor 450. If the object is within the borders of the window, position adjuster 432 passes the object to conventional video buffer 438 for display on conventional display 442 via conventional video driver 440. If the object is outside or partially outside the window, position adjuster adjusts display characteristics of the object such as the coordinates, size, shape, color or display intensity of the object or objects received at input 430 to cause the object to be fully or partially positioned within the borders of the window as described above with reference to Figure 3A, prior to copying via output 436 the object with the adjusted coordinates to conventional video buffer 438 for display on conventional display 442 via conventional video driver 440. Because position adjuster 432 only alters the coordinates of the copy it receives via input 430 of the object stored in object storage 410, the original coordinates of the object stored in object storage 410 are unchanged, so that the apparatus 400 may repeat the procedure described herein when the window is moved or resized without separately undertaking the preservation of the original characteristics of the object stored in object storage 410.
Referring now to Figure 5A, one embodiment of a position adjuster 432 of Figure 4 is shown. Window coordinates are input via input 434 to window coordinate storage 510 which stores the window coordinates, such as the two coordinate pairs described above, to allow position adjuster 432 to identify the size and location of the window. Optional object storage 512 accepts object information including characteristics such as the coordinates and optionally, the size of the object via input 430. Comparator 514 has one input coupled to window coordinate storage 510 and another input coupled to object storage 512, and compares the size and position of the object to the coordinates of the window to determine whether the coordinates and size of the object are such that the object will not be displayed fully within the window without
adjustment. In this case, output 515 signals adjuster 516 to adjust the one or more of the characteristics such as the coordinates, color, display intensity, size or shape of the object so that it will be displayed either fully or partially within the window as described above with reference to Figure 3A. If so signaled by line 515, adjuster 516 computes the new position coordinates, size, shape or other characteristics of the object and writes them via line 517 in place of the values stored in object storage 512 or transfers the new values or original values directly to output 436 depending on the signal 515 received from comparator 514. Object store then writes the object to output 436. Optional timer 518 controls the timing of the comparator 514, adjuster 516 and object storage 512 so that the compare occurs first, any adjustment occurs next, and object storage 512 writes to output 436 last.
Referring now to Figure 5B, the comparator 514 of Figure 5A is shown in more detail according to one embodiment of the present invention. In one embodiment, the window is always in the shape of a rectangle defined by two coordinate pairs, and each object is identified by the two coordinate pairs corresponding to the position and size of the smallest rectangle that would contain the object. Window coordinate storage 510 stores in storage devices 520A, 520B, 520C, 520D the two display coordinate pairs from each of the two opposite corners of the window described above with reference to Figure 3A. Object storage 512 stores in storage devices 522A, 522B, 522C, 522D the two display coordinates from each of the two opposite corners of the smallest rectangle that surrounds the displayed object. Comparator 514 contains comparators 524A, 524B, 524C, 524D coupled to each of the corresponding coordinates 520A, 520B, 520C, 520D, 522A, 522B, 522C, 522D so that they signal the same logic level if the leftmost display coordinate of the object is greater than the leftmost display coordinate of the window, the rightmost display coordinate of the object is less than the rightmost display coordinate of the window, the topmost display coordinate of the object is greater than the topmost display coordinate of the window, and the bottommost display coordinate of the object is less than the bottommost display coordinate of the window. The outputs 528A, 528B, 528C, 528D of each comparator 524A, 524B, 524C, 524D are the output 515 of comparator 514 shown in Figure 5A.
Referring now to Figure 5C, the adjuster 516 of Figure 5A is shown in more detail according to one embodiment of the present invention. Window coordinate storage 510 and object storage 512 are arranged as described above with respect to Figure 5B. Computational units 530A, 530B, 530C, 530D have inputs 529 A, 529B, 529C, 529D, which are respectively coupled to outputs 528A,
528B, 528C, 528D of the comparator 514 Figure 5B. Multiplexors within computational units 530A, 530B, 530C, 530D select the original coordinate of the object if that coordinate is within the window, and the corresponding border coordinate of the window if the coordinate of the object is outside the window, and the difference between the original coordinate of the object and the coordinate of the window is computed and sent to the computational units 530A, 530B, 530C, 530D corresponding to the opposite side of the object (i.e. left is opposite right, top is opposite bottom) to allow for a similar adjustment of the opposite side to preserve the size and shape of the object. In another embodiment, the coordinate of the side originally outside the window is also communicated to computational unit 530A, 530B, 530C, 530D of the opposite side to allow the computational unit 530A, 530B, 530C, 530D of the opposite side to adjust the coordinate of the opposite side so as to adjust the dimension of the object between the two opposite sides if such dimension exceeds a certain maximum size.
Referring now to Figures 5C and 5D, one embodiment of a computational unit 530A of Figure 5C according to the present invention is shown. Multiplexor 562 selects as the output 568 coupled to the corresponding output 532, the coordinate of the object at input 550 when the condition of no adjustment is required, the corresponding coordinate of the window at input
556 when the condition of adjustment to the edge of the window is required, or the adjusted coordinate of the object computed by Arithmetic Logic Unit (ALU) 560 corresponding to the sum of the coordinate of the object at input 550 and the difference of the opposite side of the object at input 552 when the condition of the coordinate requiring adjustment in response to an adjustment of the coordinate of the opposite side of the object. The conditions (no adjustment, adjust to edge of window, or adjust in response to adjustment of opposite side) are identified by the selection inputs 529 A, 529C both inactive, 529A active and 529C inactive, or 529A inactive and 529C active, respectively. ALU 564 computes the difference of the object coordinate at its A input and the output
568 of multiplexor 562 to provide as opposite side difference input 552 of computational unit 530C.
Referring now to Figure 5E, one embodiment of an apparatus which assigns a color to an object according to the level of the object in a hierarchy is shown. The apparatus in the Figure may be used prior to the object input into the apparatus of Figure 5A In one embodiment, eight colors are each assigned a unique number 0 to 7 and hierarchy levels are assigned a color according to their level in the hierarchy mod 8. Hierarchy input 540 accepts the least
significant three bits of the binary number representing the hierarchy of the object and passes the bits to an address input 541 of an 8x8 memory 542. The colors for each level are stored in each memory location at the address corresponding to the input. Data output 543 of memory 542 passes a color code which may be copied into the offscreen buffer at the bit locations corresponding to the object by conventional rendering devices.
The apparatus or methods of the present invention described above may be implemented in software on a conventional computer system in a preferred embodiment. As shown in Figure 6, a conventional computer system 609 includes a processor 601 coupled to a first storage device 603 such as a memory, and a second storage device 608 such as a disk storage system. A user may interact with the system via a keyboard 604, mouse 605 and a display 606. Computer program product reader 607, such as a memory, hard drive, floppy disk drive or CD-ROM drive can is coupled to processor 601 to allow computer readable program code devices 611 such as encoded bits of a computer program product 610 such as a memory, hard disk, floppy disk, CD-ROM or other storage device to be read and their contents input to processor 601 and stored in memory 603 and /or disk storage 608 for use in controlling the operation of the computer system 609 when computer program product 610 is inserted into slot 612 of computer program product reader 607 or when computer program product 610 is otherwise activated. Communication interface 613 such as a modem may also be coupled to processor 601 to allow for remote retrieval of computer readable program code devices for storage on memory 603 or disk storage 608. An operating system is loaded into memory 603 or disk storage 608 or a combination of memory 603 and disk storage 608 and instructs processor 601 to load and execute computer program products from computer program product 610 or other storage devices 603, 608 comprising applications such as those which display objects as described above. Many conventional applications are distributed on computer program products 610, such as diskettes, storage devices such as ROMs or disk storage systems, each containing computer readable code devices 611 which cause the computer system 609 to operate in a particular manner such as is described herein when a copy of the code devices is loaded into the computer system 609.
In one embodiment, the methods and apparati described herein are implemented in software and copied and distributed on a computer program product to operate on a conventional computer system such as the computer system 609 shown in Figure 6.