1 /***************************************************************************
2  * Copyright (c) 2024 Microsoft Corporation
3  *
4  * This program and the accompanying materials are made available under the
5  * terms of the MIT License which is available at
6  * https://opensource.org/licenses/MIT.
7  *
8  * SPDX-License-Identifier: MIT
9  **************************************************************************/
10 
11 
12 /**************************************************************************/
13 /**************************************************************************/
14 /**                                                                       */
15 /** GUIX Component                                                        */
16 /**                                                                       */
17 /**   Widget Management (Widget)                                          */
18 /**                                                                       */
19 /**************************************************************************/
20 
21 #define GX_SOURCE_CODE
22 
23 
24 /* Include necessary system files.  */
25 
26 #include "gx_api.h"
27 #include "gx_system.h"
28 #include "gx_widget.h"
29 #include "gx_utility.h"
30 
31 
32 /**************************************************************************/
33 /*                                                                        */
34 /*  FUNCTION                                               RELEASE        */
35 /*                                                                        */
36 /*    _gx_widget_unlink                                   PORTABLE C      */
37 /*                                                           6.1          */
38 /*  AUTHOR                                                                */
39 /*                                                                        */
40 /*    Kenneth Maxwell, Microsoft Corporation                              */
41 /*                                                                        */
42 /*  DESCRIPTION                                                           */
43 /*                                                                        */
44 /*    This function unlinks a widget.                                     */
45 /*                                                                        */
46 /*  INPUT                                                                 */
47 /*                                                                        */
48 /*    widget                                Widget control block          */
49 /*                                                                        */
50 /*  OUTPUT                                                                */
51 /*                                                                        */
52 /*    GX_WIDET *                            Widget being unlinked         */
53 /*                                                                        */
54 /*  CALLS                                                                 */
55 /*                                                                        */
56 /*    None                                                                */
57 /*                                                                        */
58 /*  CALLED BY                                                             */
59 /*                                                                        */
60 /*    GUIX Internal Code                                                  */
61 /*                                                                        */
62 /*  RELEASE HISTORY                                                       */
63 /*                                                                        */
64 /*    DATE              NAME                      DESCRIPTION             */
65 /*                                                                        */
66 /*  05-19-2020     Kenneth Maxwell          Initial Version 6.0           */
67 /*  09-30-2020     Kenneth Maxwell          Modified comment(s),          */
68 /*                                            resulting in version 6.1    */
69 /*                                                                        */
70 /**************************************************************************/
_gx_widget_unlink(GX_WIDGET * widget)71 GX_WIDGET *_gx_widget_unlink(GX_WIDGET *widget)
72 {
73 
74 GX_WIDGET *sibling;
75 GX_WIDGET *parent;
76 
77     /* Determine if the widget has a parent.  */
78     parent = widget -> gx_widget_parent;
79 
80     if (parent)
81     {
82         /* Is this widget the first child? */
83         if (parent -> gx_widget_first_child == widget)
84         {
85             /* Yes, unlink and done*/
86             parent -> gx_widget_first_child = widget -> gx_widget_next;
87             if (parent -> gx_widget_first_child)
88             {
89                 parent -> gx_widget_first_child -> gx_widget_previous = GX_NULL;
90             }
91 
92             /* if last was also pointing at this widget, then it was the only
93                child. Update last pointer: */
94             if (parent -> gx_widget_last_child == widget)
95             {
96                 parent -> gx_widget_last_child = parent -> gx_widget_first_child;
97             }
98         }
99         else
100         {
101             sibling = parent -> gx_widget_first_child;
102 
103             while (sibling -> gx_widget_next != widget)
104             {
105                 sibling = sibling -> gx_widget_next;
106             }
107             sibling -> gx_widget_next = widget -> gx_widget_next;
108 
109             if (parent -> gx_widget_last_child == widget)
110             {
111                 parent -> gx_widget_last_child = sibling;
112             }
113 
114             if (sibling -> gx_widget_next)
115             {
116                 sibling -> gx_widget_next -> gx_widget_previous = sibling;
117             }
118         }
119         if (widget -> gx_widget_status & GX_STATUS_VISIBLE)
120         {
121             _gx_widget_hide(widget);
122         }
123         widget -> gx_widget_parent = GX_NULL;
124         widget -> gx_widget_next = GX_NULL;
125         widget -> gx_widget_previous = GX_NULL;
126         widget -> gx_widget_nav_next = GX_NULL;
127         widget -> gx_widget_nav_previous = GX_NULL;
128     }
129     /* Return widget pointer  */
130     return(widget);
131 }
132 
133