GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: gx_scrollbar_value_calculate.c Lines: 34 34 100.0 %
Date: 2024-12-05 08:52:37 Branches: 8 8 100.0 %

Line Branch Exec Source
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/***************************************************************************
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 * Copyright (c) 2024 Microsoft Corporation
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 *
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 * This program and the accompanying materials are made available under the
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 * terms of the MIT License which is available at
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 * https://opensource.org/licenses/MIT.
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 *
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 * SPDX-License-Identifier: MIT
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 **************************************************************************/
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/**************************************************************************/
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/**************************************************************************/
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/**                                                                       */
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/** GUIX Component                                                        */
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/**                                                                       */
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/**   Scrollbar Management (Scrollbar)                                    */
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/**                                                                       */
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/**************************************************************************/
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#define GX_SOURCE_CODE
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/* Include necessary system files.  */
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#include "gx_api.h"
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#include "gx_system.h"
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#include "gx_display.h"
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#include "gx_context.h"
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#include "gx_widget.h"
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#include "gx_utility.h"
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#include "gx_scrollbar.h"
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/**************************************************************************/
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/*                                                                        */
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/*  FUNCTION                                               RELEASE        */
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/*                                                                        */
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/*    _gx_scrollbar_value_calculate                       PORTABLE C      */
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/*                                                           6.1          */
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/*  AUTHOR                                                                */
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/*                                                                        */
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/*    Kenneth Maxwell, Microsoft Corporation                              */
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/*                                                                        */
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/*  DESCRIPTION                                                           */
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/*                                                                        */
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/*    Calculate new scrollbar value give thumb button offset and size     */
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/*                                                                        */
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/*                                                                        */
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/*  INPUT                                                                 */
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/*                                                                        */
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/*    scroll                                Scrollbar control block       */
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/*    offset                                Thumb button offset           */
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/*    size                                  Thumb button height           */
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/*                                            (vertical) or width         */
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/*                                            (horizontal)                */
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/*                                                                        */
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/*  OUTPUT                                                                */
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/*                                                                        */
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/*    None                                                                */
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/*                                                                        */
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/*  CALLS                                                                 */
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/*                                                                        */
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/*    [gx_widget_event_process_function]    Parent widget event process   */
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/*                                            function                    */
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/*                                                                        */
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/*  CALLED BY                                                             */
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/*                                                                        */
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/*    GUIX Internal Code                                                  */
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/*                                                                        */
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/*  RELEASE HISTORY                                                       */
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/*                                                                        */
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/*    DATE              NAME                      DESCRIPTION             */
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/*                                                                        */
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/*  05-19-2020     Kenneth Maxwell          Initial Version 6.0           */
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/*  09-30-2020     Kenneth Maxwell          Modified comment(s),          */
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/*                                            resulting in version 6.1    */
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/*                                                                        */
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/**************************************************************************/
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VOID _gx_scrollbar_value_calculate(GX_SCROLLBAR *scroll, INT offset, INT size)
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{
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GX_EVENT   newevent;
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INT        newval;
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INT        oldval;
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INT        travel;
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UINT       style;
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    /* calculate range of allowed values */
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    newval = (scroll -> gx_scrollbar_info.gx_scroll_maximum -
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              scroll -> gx_scrollbar_info.gx_scroll_minimum) -
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              scroll -> gx_scrollbar_info.gx_scroll_visible + 1;
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    /* scale this by distance thumb has traveled from minimum */
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    style = scroll -> gx_widget_style;
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    if (style & GX_SCROLLBAR_VERTICAL)
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    {
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        newval *= offset - (scroll -> gx_widget_size.gx_rectangle_top +
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                            scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_min);
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        /* calculate total travel allowed */
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        travel = (scroll -> gx_widget_size.gx_rectangle_bottom -
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                  scroll -> gx_widget_size.gx_rectangle_top) + 1;
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    }
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    else
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    {
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        newval *= offset - (scroll -> gx_widget_size.gx_rectangle_left +
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                            scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_min);
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        /* calculate total travel allowed */
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        travel = (scroll -> gx_widget_size.gx_rectangle_right -
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                  scroll -> gx_widget_size.gx_rectangle_left) + 1;
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    }
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    travel -= scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_max +
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              scroll -> gx_scrollbar_appearance.gx_scroll_thumb_travel_min;
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    travel -= size;
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    /* scale the value using linear interpolation */
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    if (travel)
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    {
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        newval = (newval + (travel >> 1)) / travel;
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    }
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    /* offset the value based on minimum */
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    newval += scroll -> gx_scrollbar_info.gx_scroll_minimum;
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    /* make sure we stay within desired range */
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    oldval = scroll -> gx_scrollbar_info.gx_scroll_value;
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    scroll -> gx_scrollbar_info.gx_scroll_value = newval;
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    _gx_scrollbar_limit_check(scroll);
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    /* if the value has changed, send a scroll event to my parent */
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    if (scroll -> gx_scrollbar_info.gx_scroll_value != oldval)
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    {
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        /* pass the old value in data[1] */
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        newevent.gx_event_payload.gx_event_intdata[1] = oldval;
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        newevent.gx_event_payload.gx_event_intdata[0] = scroll -> gx_scrollbar_info.gx_scroll_value;
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        if (style & GX_SCROLLBAR_VERTICAL)
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        {
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            newevent.gx_event_sender = GX_ID_VERTICAL_SCROLL;
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            newevent.gx_event_type = GX_EVENT_VERTICAL_SCROLL;
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        }
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        else
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        {
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            newevent.gx_event_sender = GX_ID_HORIZONTAL_SCROLL;
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            newevent.gx_event_type = GX_EVENT_HORIZONTAL_SCROLL;
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        }
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        /* send event to my parent window */
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        newevent.gx_event_target = scroll -> gx_widget_parent;
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        _gx_system_event_send(&newevent);
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    }
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}
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