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 /** Scrollbar Management (Scrollbar) */ 18 /** */ 19 /**************************************************************************/ 20 21 #define GX_SOURCE_CODE 22 23 /* Include necessary system files. */ 24 25 #include "gx_api.h" 26 #include "gx_system.h" 27 #include "gx_display.h" 28 #include "gx_context.h" 29 #include "gx_widget.h" 30 #include "gx_utility.h" 31 #include "gx_scrollbar.h" 32 33 /**************************************************************************/ 34 /* */ 35 /* FUNCTION RELEASE */ 36 /* */ 37 /* _gx_scrollbar_value_calculate PORTABLE C */ 38 /* 6.1 */ 39 /* AUTHOR */ 40 /* */ 41 /* Kenneth Maxwell, Microsoft Corporation */ 42 /* */ 43 /* DESCRIPTION */ 44 /* */ 45 /* Calculate new scrollbar value give thumb button offset and size */ 46 /* */ 47 /* */ 48 /* INPUT */ 49 /* */ 50 /* scroll Scrollbar control block */ 51 /* offset Thumb button offset */ 52 /* size Thumb button height */ 53 /* (vertical) or width */ 54 /* (horizontal) */ 55 /* */ 56 /* OUTPUT */ 57 /* */ 58 /* None */ 59 /* */ 60 /* CALLS */ 61 /* */ 62 /* [gx_widget_event_process_function] Parent widget event process */ 63 /* function */ 64 /* */ 65 /* CALLED BY */ 66 /* */ 67 /* GUIX Internal Code */ 68 /* */ 69 /* RELEASE HISTORY */ 70 /* */ 71 /* DATE NAME DESCRIPTION */ 72 /* */ 73 /* 05-19-2020 Kenneth Maxwell Initial Version 6.0 */ 74 /* 09-30-2020 Kenneth Maxwell Modified comment(s), */ 75 /* resulting in version 6.1 */ 76 /* */ 77 /**************************************************************************/ _gx_scrollbar_value_calculate(GX_SCROLLBAR * scroll,INT offset,INT size)78VOID _gx_scrollbar_value_calculate(GX_SCROLLBAR *scroll, INT offset, INT size) 79 { 80 GX_EVENT newevent; 81 INT newval; 82 INT oldval; 83 INT travel; 84 UINT style; 85 86 /* calculate range of allowed values */ 87 newval = (scroll -> gx_scrollbar_info.gx_scroll_maximum - 88 scroll -> gx_scrollbar_info.gx_scroll_minimum) - 89 scroll -> gx_scrollbar_info.gx_scroll_visible + 1; 90 91 /* scale this by distance thumb has traveled from minimum */ 92 style = scroll -> gx_widget_style; 93 94 if (style & GX_SCROLLBAR_VERTICAL) 95 { 96 newval *= offset - (scroll -> gx_widget_size.gx_rectangle_top + 97 scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_min); 98 99 /* calculate total travel allowed */ 100 travel = (scroll -> gx_widget_size.gx_rectangle_bottom - 101 scroll -> gx_widget_size.gx_rectangle_top) + 1; 102 } 103 else 104 { 105 newval *= offset - (scroll -> gx_widget_size.gx_rectangle_left + 106 scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_min); 107 108 /* calculate total travel allowed */ 109 travel = (scroll -> gx_widget_size.gx_rectangle_right - 110 scroll -> gx_widget_size.gx_rectangle_left) + 1; 111 } 112 113 travel -= scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_max + 114 scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_min; 115 116 travel -= size; 117 118 /* scale the value using linear interpolation */ 119 if (travel) 120 { 121 newval = (newval + (travel >> 1)) / travel; 122 } 123 124 /* offset the value based on minimum */ 125 newval += scroll -> gx_scrollbar_info.gx_scroll_minimum; 126 127 /* make sure we stay within desired range */ 128 oldval = scroll -> gx_scrollbar_info.gx_scroll_value; 129 scroll -> gx_scrollbar_info.gx_scroll_value = newval; 130 _gx_scrollbar_limit_check(scroll); 131 132 /* if the value has changed, send a scroll event to my parent */ 133 if (scroll -> gx_scrollbar_info.gx_scroll_value != oldval) 134 { 135 /* pass the old value in data[1] */ 136 newevent.gx_event_payload.gx_event_intdata[1] = oldval; 137 newevent.gx_event_payload.gx_event_intdata[0] = scroll -> gx_scrollbar_info.gx_scroll_value; 138 139 if (style & GX_SCROLLBAR_VERTICAL) 140 { 141 newevent.gx_event_sender = GX_ID_VERTICAL_SCROLL; 142 newevent.gx_event_type = GX_EVENT_VERTICAL_SCROLL; 143 } 144 else 145 { 146 newevent.gx_event_sender = GX_ID_HORIZONTAL_SCROLL; 147 newevent.gx_event_type = GX_EVENT_HORIZONTAL_SCROLL; 148 } 149 150 /* send event to my parent window */ 151 newevent.gx_event_target = scroll -> gx_widget_parent; 152 _gx_system_event_send(&newevent); 153 } 154 } 155 156
