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 /** Vertical List Management */ 18 /** */ 19 /**************************************************************************/ 20 21 #define GX_SOURCE_CODE 22 23 24 /* Include necessary system files. */ 25 26 #include "gx_api.h" 27 #include "gx_widget.h" 28 #include "gx_window.h" 29 #include "gx_system.h" 30 #include "gx_scrollbar.h" 31 32 /**************************************************************************/ 33 /* */ 34 /* FUNCTION RELEASE */ 35 /* */ 36 /* _gx_vertical_list_scroll_info_get PORTABLE C */ 37 /* 6.4.0 */ 38 /* AUTHOR */ 39 /* */ 40 /* Kenneth Maxwell, Microsoft Corporation */ 41 /* */ 42 /* DESCRIPTION */ 43 /* */ 44 /* This function gets the scrollbar information. */ 45 /* */ 46 /* INPUT */ 47 /* */ 48 /* win Pointer to window */ 49 /* style Style */ 50 /* info Information of scrollbar */ 51 /* */ 52 /* OUTPUT */ 53 /* */ 54 /* None */ 55 /* */ 56 /* CALLS */ 57 /* */ 58 /* _gx_first_client_child_get Get the first client child */ 59 /* */ 60 /* CALLED BY */ 61 /* */ 62 /* Application Code */ 63 /* */ 64 /* RELEASE HISTORY */ 65 /* */ 66 /* DATE NAME DESCRIPTION */ 67 /* */ 68 /* 05-19-2020 Kenneth Maxwell Initial Version 6.0 */ 69 /* 09-30-2020 Kenneth Maxwell Modified comment(s), */ 70 /* resulting in version 6.1 */ 71 /* 12-31-2023 Ting Zhu Modified comments(s), */ 72 /* improved the calculation of */ 73 /* the maximum scrolling value.*/ 74 /* resulting in version 6.4.0 */ 75 /* */ 76 /**************************************************************************/ _gx_vertical_list_scroll_info_get(GX_VERTICAL_LIST * list,ULONG style,GX_SCROLL_INFO * info)77VOID _gx_vertical_list_scroll_info_get(GX_VERTICAL_LIST *list, ULONG style, GX_SCROLL_INFO *info) 78 { 79 INT value; 80 GX_VALUE height; 81 GX_WIDGET *child; 82 83 GX_PARAMETER_NOT_USED(style); 84 85 if (list -> gx_vertical_list_callback) 86 { 87 /* If list callback is set, children winthin the list should share the same height. */ 88 info -> gx_scroll_maximum = (list->gx_vertical_list_total_rows * list -> gx_vertical_list_child_height - 1); 89 } 90 else 91 { 92 info -> gx_scroll_maximum = 0; 93 94 child = _gx_widget_first_client_child_get((GX_WIDGET *)list); 95 96 while (child) 97 { 98 _gx_widget_height_get(child, &height); 99 100 info -> gx_scroll_maximum += height; 101 102 child = _gx_widget_next_client_child_get(child); 103 } 104 } 105 info -> gx_scroll_minimum = 0; 106 info -> gx_scroll_visible = (GX_VALUE)(list -> gx_window_client.gx_rectangle_bottom - list -> gx_window_client.gx_rectangle_top + 1); 107 108 if (info -> gx_scroll_maximum <= info -> gx_scroll_visible) 109 { 110 info -> gx_scroll_value = 0; 111 info -> gx_scroll_increment = 0; 112 info -> gx_scroll_maximum = info->gx_scroll_visible; 113 return; 114 } 115 116 value = list -> gx_vertical_list_top_index * list -> gx_vertical_list_child_height; 117 118 if (list -> gx_vertical_list_top_index >= 0) 119 { 120 child = _gx_widget_first_client_child_get((GX_WIDGET *)list); 121 122 if (child) 123 { 124 value += list -> gx_window_client.gx_rectangle_top - child -> gx_widget_size.gx_rectangle_top; 125 } 126 } 127 128 if (value < info -> gx_scroll_minimum) 129 { 130 value = info -> gx_scroll_minimum; 131 } 132 else 133 { 134 if (value > info -> gx_scroll_maximum - info -> gx_scroll_visible + 1) 135 { 136 value = info -> gx_scroll_maximum - info -> gx_scroll_visible + 1; 137 } 138 } 139 140 info -> gx_scroll_value = value; 141 info -> gx_scroll_increment = list -> gx_vertical_list_child_height / 2; 142 } 143 144
