ref: f8a450f494e1ab5b6dbe915331e13abe03c298b3
dir: /textscreen/txt_table.c/
//
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include "doomkeys.h"
#include "txt_desktop.h"
#include "txt_gui.h"
#include "txt_io.h"
#include "txt_main.h"
#include "txt_separator.h"
#include "txt_strut.h"
#include "txt_table.h"
txt_widget_t txt_table_overflow_right;
txt_widget_t txt_table_overflow_down;
txt_widget_t txt_table_eol;
txt_widget_t txt_table_empty;
// Returns true if the given widget in the table's widgets[] array refers
// to an actual widget - not NULL, or one of the special overflow pointers.
static int IsActualWidget(txt_widget_t *widget)
{
return widget != NULL
&& widget != &txt_table_overflow_right
&& widget != &txt_table_overflow_down;
}
// Remove all entries from a table
void TXT_ClearTable(TXT_UNCAST_ARG(table))
{
TXT_CAST_ARG(txt_table_t, table);
int i;
// Free all widgets
// Skip over the first (num_columns) widgets in the array, as these
// are the column struts used to control column width
for (i=table->columns; i<table->num_widgets; ++i)
{
if (IsActualWidget(table->widgets[i]))
{
TXT_DestroyWidget(table->widgets[i]);
}
}
// Shrink the table to just the column strut widgets
table->num_widgets = table->columns;
}
static void TXT_TableDestructor(TXT_UNCAST_ARG(table))
{
TXT_CAST_ARG(txt_table_t, table);
TXT_ClearTable(table);
}
static int TableRows(txt_table_t *table)
{
return (table->num_widgets + table->columns - 1) / table->columns;
}
// Most widgets occupy just one cell of a table, but if the special
// overflow constants are used, they can occupy multiple cells.
// This function figures out for a widget in a given cell, which
// cells it should actually occupy (always a rectangle).
static void CellOverflowedSize(txt_table_t *table, int x, int y,
int *w, int *h)
{
txt_widget_t *widget;
int x1, y1;
if (!IsActualWidget(table->widgets[y * table->columns + x]))
{
*w = 0; *h = 0;
return;
}
*w = table->columns - x;
*h = 0;
for (y1 = y; y1 < TableRows(table); ++y1)
{
// Every overflow cell must point to either (x, y) or another
// overflow cell. This means the first in every row must be
// txt_table_overflow_down.
if (y1 * table->columns + x >= table->num_widgets)
{
break;
}
widget = table->widgets[y1 * table->columns + x];
if (y1 != y && widget != &txt_table_overflow_down)
{
break;
}
for (x1 = x + 1; x1 < x + *w; ++x1)
{
if (y1 * table->columns + x1 >= table->num_widgets)
{
break;
}
// Can be either type of overflow, except on the first row.
// Otherwise we impose a limit on the width.
widget = table->widgets[y1 * table->columns + x1];
if (widget != &txt_table_overflow_right
&& (widget != &txt_table_overflow_down || y1 == y))
{
*w = x1 - x;
break;
}
}
++*h;
}
}
static int IsOverflowingCell(txt_table_t *table, int x, int y)
{
int w, h;
CellOverflowedSize(table, x, y, &w, &h);
return w > 1 || h > 1;
}
// Using the given column/row size tables, calculate the size of the given
// widget, storing the result in (w, h).
static void CalculateWidgetDimensions(txt_table_t *table,
int x, int y,
unsigned int *column_widths,
unsigned int *row_heights,
unsigned int *w, unsigned int *h)
{
int cell_w, cell_h;
int x1, y1;
// Find which cells this widget occupies.
CellOverflowedSize(table, x, y, &cell_w, &cell_h);
// Add up column / row widths / heights to get the actual dimensions.
*w = 0;
for (x1 = x; x1 < x + cell_w; ++x1)
{
*w += column_widths[x1];
}
*h = 0;
for (y1 = y; y1 < y + cell_h; ++y1)
{
*h += row_heights[y1];
}
}
static void CalcRowColSizes(txt_table_t *table,
unsigned int *row_heights,
unsigned int *col_widths)
{
int x, y;
int rows;
txt_widget_t *widget;
rows = TableRows(table);
memset(col_widths, 0, sizeof(int) * table->columns);
for (y = 0; y < rows; ++y)
{
row_heights[y] = 0;
for (x = 0; x < table->columns; ++x)
{
if (y * table->columns + x >= table->num_widgets)
break;
widget = table->widgets[y * table->columns + x];
if (IsActualWidget(widget))
{
TXT_CalcWidgetSize(widget);
}
// In the first pass we ignore overflowing cells.
if (IsOverflowingCell(table, x, y))
{
continue;
}
// NULL represents an empty spacer
if (IsActualWidget(widget))
{
if (widget->h > row_heights[y])
row_heights[y] = widget->h;
if (widget->w > col_widths[x])
col_widths[x] = widget->w;
}
}
}
// In the second pass, we go through again and process overflowing
// widgets, to ensure that they will fit.
for (y = 0; y < rows; ++y)
{
for (x = 0; x < table->columns; ++x)
{
unsigned int w, h;
if (y * table->columns + x >= table->num_widgets)
break;
widget = table->widgets[y * table->columns + x];
if (!IsActualWidget(widget))
{
continue;
}
// Expand column width and row heights as needed.
CalculateWidgetDimensions(table, x, y, col_widths, row_heights,
&w, &h);
if (w < widget->w)
{
col_widths[x] += widget->w - w;
}
if (h < widget->h)
{
row_heights[y] += widget->h - h;
}
}
}
}
static void TXT_CalcTableSize(TXT_UNCAST_ARG(table))
{
TXT_CAST_ARG(txt_table_t, table);
unsigned int *column_widths;
unsigned int *row_heights;
int x, y;
int rows;
rows = TableRows(table);
row_heights = malloc(sizeof(int) * rows);
column_widths = malloc(sizeof(int) * table->columns);
CalcRowColSizes(table, row_heights, column_widths);
table->widget.w = 0;
for (x=0; x<table->columns; ++x)
{
table->widget.w += column_widths[x];
}
table->widget.h = 0;
for (y=0; y<rows; ++y)
{
table->widget.h += row_heights[y];
}
free(row_heights);
free(column_widths);
}
static void FillRowToEnd(txt_table_t *table)
{
while ((table->num_widgets % table->columns) != 0)
{
TXT_AddWidget(table, &txt_table_overflow_right);
}
}
void TXT_AddWidget(TXT_UNCAST_ARG(table), TXT_UNCAST_ARG(widget))
{
TXT_CAST_ARG(txt_table_t, table);
TXT_CAST_ARG(txt_widget_t, widget);
int is_separator;
int i;
// Convenience alias for NULL:
if (widget == &txt_table_empty)
{
widget = NULL;
}
else if (widget == &txt_table_eol)
{
FillRowToEnd(table);
return;
}
// We have special handling for the separator widget:
is_separator = IsActualWidget(widget)
&& widget->widget_class == &txt_separator_class;
// If we add two separators consecutively, the new separator replaces the
// first. This allows us to override the "implicit" separator that is
// added at the top of a window when it is created.
if (is_separator)
{
for (i = table->num_widgets - 1; i >= 0; --i)
{
txt_widget_t *last_widget;
last_widget = table->widgets[i];
if (IsActualWidget(last_widget)
&& widget->widget_class == &txt_separator_class
&& last_widget->widget_class == &txt_separator_class)
{
table->widgets[i] = widget;
TXT_DestroyWidget(last_widget);
return;
}
else if (last_widget != &txt_table_overflow_right)
{
break;
}
}
}
// Separators begin on a new line.
if (is_separator)
{
FillRowToEnd(table);
}
table->widgets = realloc(table->widgets,
sizeof(txt_widget_t *) * (table->num_widgets + 1));
table->widgets[table->num_widgets] = widget;
++table->num_widgets;
// Maintain parent pointer.
if (IsActualWidget(widget))
{
widget->parent = &table->widget;
}
// Separators always take up the entire line.
if (is_separator)
{
FillRowToEnd(table);
}
}
// Add multiple widgets to a table.
void TXT_AddWidgets(TXT_UNCAST_ARG(table), ...)
{
TXT_CAST_ARG(txt_table_t, table);
va_list args;
txt_widget_t *widget;
va_start(args, TXT_UNCAST_ARG_NAME(table));
// Keep adding widgets until a NULL is reached.
for (;;)
{
widget = va_arg(args, txt_widget_t *);
if (widget == NULL)
{
break;
}
TXT_AddWidget(table, widget);
}
va_end(args);
}
static int SelectableCell(txt_table_t *table, int x, int y)
{
txt_widget_t *widget;
int i;
if (x < 0 || x >= table->columns)
{
return 0;
}
i = y * table->columns + x;
if (i >= 0 && i < table->num_widgets)
{
widget = table->widgets[i];
return IsActualWidget(widget)
&& TXT_SelectableWidget(widget)
&& widget->visible;
}
return 0;
}
// Tries to locate a selectable widget in the given row, returning
// the column number of the first column available or -1 if none are
// available in the given row.
//
// Starts from start_col, then searches nearby columns.
static int FindSelectableColumn(txt_table_t *table, int row, int start_col)
{
int x;
for (x=0; x<table->columns; ++x)
{
// Search to the right
if (SelectableCell(table, start_col + x, row))
{
return start_col + x;
}
// Search to the left
if (SelectableCell(table, start_col - x, row))
{
return start_col - x;
}
}
// None available
return -1;
}
// Change the selected widget.
static void ChangeSelection(txt_table_t *table, int x, int y)
{
txt_widget_t *cur_widget;
txt_widget_t *new_widget;
int i;
// No change?
if (x == table->selected_x && y == table->selected_y)
{
return;
}
// Unfocus current widget:
i = table->selected_y * table->columns + table->selected_x;
if (i < table->num_widgets)
{
cur_widget = table->widgets[i];
if (table->widget.focused && IsActualWidget(cur_widget))
{
TXT_SetWidgetFocus(cur_widget, 0);
}
}
// Focus new widget.
new_widget = table->widgets[y * table->columns + x];
table->selected_x = x;
table->selected_y = y;
if (table->widget.focused && new_widget != NULL)
{
TXT_SetWidgetFocus(new_widget, 1);
}
}
static int TXT_TableKeyPress(TXT_UNCAST_ARG(table), int key)
{
TXT_CAST_ARG(txt_table_t, table);
int selected;
int rows;
rows = TableRows(table);
// Send to the currently selected widget first
selected = table->selected_y * table->columns + table->selected_x;
if (selected >= 0 && selected < table->num_widgets)
{
if (IsActualWidget(table->widgets[selected])
&& TXT_SelectableWidget(table->widgets[selected])
&& TXT_WidgetKeyPress(table->widgets[selected], key))
{
return 1;
}
}
if (key == KEY_TAB)
{
int dir;
int i;
dir = TXT_GetModifierState(TXT_MOD_SHIFT) ? -1 : 1;
// Cycle through all widgets until we find one that can be selected.
for (i = table->selected_y * table->columns + table->selected_x + dir;
i >= 0 && i < table->num_widgets;
i += dir)
{
if (IsActualWidget(table->widgets[i])
&& TXT_SelectableWidget(table->widgets[i]))
{
ChangeSelection(table, i % table->columns, i / table->columns);
return 1;
}
}
return 0;
}
if (key == KEY_DOWNARROW)
{
int new_x, new_y;
// Move cursor down to the next selectable widget
for (new_y = table->selected_y + 1; new_y < rows; ++new_y)
{
new_x = FindSelectableColumn(table, new_y, table->selected_x);
if (new_x >= 0)
{
// Found a selectable widget in this column!
ChangeSelection(table, new_x, new_y);
return 1;
}
}
}
if (key == KEY_UPARROW)
{
int new_x, new_y;
// Move cursor up to the next selectable widget
for (new_y = table->selected_y - 1; new_y >= 0; --new_y)
{
new_x = FindSelectableColumn(table, new_y, table->selected_x);
if (new_x >= 0)
{
// Found a selectable widget in this column!
ChangeSelection(table, new_x, new_y);
return 1;
}
}
}
if (key == KEY_LEFTARROW)
{
int new_x;
// Move cursor left
for (new_x = table->selected_x - 1; new_x >= 0; --new_x)
{
if (SelectableCell(table, new_x, table->selected_y))
{
// Found a selectable widget!
ChangeSelection(table, new_x, table->selected_y);
return 1;
}
}
}
if (key == KEY_RIGHTARROW)
{
int new_x;
// Move cursor left
for (new_x = table->selected_x + 1; new_x < table->columns; ++new_x)
{
if (SelectableCell(table, new_x, table->selected_y))
{
// Found a selectable widget!
ChangeSelection(table, new_x, table->selected_y);
return 1;
}
}
}
return 0;
}
// Check the currently selected widget in the table is valid.
static void CheckValidSelection(txt_table_t *table)
{
int rows;
int new_x, new_y;
rows = TableRows(table);
for (new_y = table->selected_y; new_y < rows; ++new_y)
{
new_x = FindSelectableColumn(table, new_y, table->selected_x);
if (new_x >= 0)
{
// Found a selectable column.
ChangeSelection(table, new_x, new_y);
break;
}
}
}
static void LayoutCell(txt_table_t *table, int x, int y,
int draw_x, int draw_y)
{
txt_widget_t *widget;
int col_width;
widget = table->widgets[y * table->columns + x];
col_width = widget->w;
// Adjust x position based on alignment property
switch (widget->align)
{
case TXT_HORIZ_LEFT:
widget->w = col_width;
break;
case TXT_HORIZ_CENTER:
TXT_CalcWidgetSize(widget);
// Separators are always drawn left-aligned.
if (widget->widget_class != &txt_separator_class)
{
draw_x += (col_width - widget->w) / 2;
}
break;
case TXT_HORIZ_RIGHT:
TXT_CalcWidgetSize(widget);
if (widget->widget_class != &txt_separator_class)
{
draw_x += col_width - widget->w;
}
break;
}
// Set the position for this widget
widget->x = draw_x;
widget->y = draw_y;
// Recursively lay out any widgets contained in the widget
TXT_LayoutWidget(widget);
}
static void TXT_TableLayout(TXT_UNCAST_ARG(table))
{
TXT_CAST_ARG(txt_table_t, table);
unsigned int *column_widths;
unsigned int *row_heights;
txt_widget_t *widget;
int draw_x, draw_y;
int x, y;
int i;
int rows;
// Work out the column widths and row heights
rows = TableRows(table);
column_widths = malloc(sizeof(int) * table->columns);
row_heights = malloc(sizeof(int) * rows);
CalcRowColSizes(table, row_heights, column_widths);
// If this table only has one column, expand column size to fit
// the display width. Ensures that separators reach the window edges
// when drawing windows.
if (table->columns == 1)
{
column_widths[0] = table->widget.w;
}
// Draw all cells
draw_y = table->widget.y;
for (y=0; y<rows; ++y)
{
draw_x = table->widget.x;
for (x=0; x<table->columns; ++x)
{
i = y * table->columns + x;
if (i >= table->num_widgets)
break;
widget = table->widgets[i];
if (IsActualWidget(widget))
{
CalculateWidgetDimensions(table, x, y,
column_widths, row_heights,
&widget->w, &widget->h);
LayoutCell(table, x, y, draw_x, draw_y);
}
draw_x += column_widths[x];
}
draw_y += row_heights[y];
}
free(row_heights);
free(column_widths);
}
static void TXT_TableDrawer(TXT_UNCAST_ARG(table))
{
TXT_CAST_ARG(txt_table_t, table);
txt_widget_t *widget;
int i;
// Check the table's current selection points at something valid before
// drawing.
CheckValidSelection(table);
// Draw all cells
for (i=0; i<table->num_widgets; ++i)
{
widget = table->widgets[i];
if (IsActualWidget(widget))
{
TXT_GotoXY(widget->x, widget->y);
TXT_DrawWidget(widget);
}
}
}
// Responds to mouse presses
static void TXT_TableMousePress(TXT_UNCAST_ARG(table), int x, int y, int b)
{
TXT_CAST_ARG(txt_table_t, table);
txt_widget_t *widget;
int i;
for (i=0; i<table->num_widgets; ++i)
{
widget = table->widgets[i];
// NULL widgets are spacers
if (IsActualWidget(widget))
{
if (x >= widget->x && x < (signed) (widget->x + widget->w)
&& y >= widget->y && y < (signed) (widget->y + widget->h))
{
// This is the widget that was clicked!
// Select the cell if the widget is selectable
if (TXT_SelectableWidget(widget))
{
ChangeSelection(table, i % table->columns,
i / table->columns);
}
// Propagate click
TXT_WidgetMousePress(widget, x, y, b);
break;
}
}
}
}
// Determine whether the table is selectable.
static int TXT_TableSelectable(TXT_UNCAST_ARG(table))
{
TXT_CAST_ARG(txt_table_t, table);
int i;
// Is the currently-selected cell selectable?
if (SelectableCell(table, table->selected_x, table->selected_y))
{
return 1;
}
// Find the first selectable cell and set selected_x, selected_y.
for (i = 0; i < table->num_widgets; ++i)
{
if (IsActualWidget(table->widgets[i])
&& TXT_SelectableWidget(table->widgets[i]))
{
ChangeSelection(table, i % table->columns, i / table->columns);
return 1;
}
}
// No selectable widgets exist within the table.
return 0;
}
// Need to pass through focus changes to the selected child widget.
static void TXT_TableFocused(TXT_UNCAST_ARG(table), int focused)
{
TXT_CAST_ARG(txt_table_t, table);
int i;
i = table->selected_y * table->columns + table->selected_x;
if (i < table->num_widgets)
{
if (IsActualWidget(table->widgets[i]))
{
TXT_SetWidgetFocus(table->widgets[i], focused);
}
}
}
txt_widget_class_t txt_table_class =
{
TXT_TableSelectable,
TXT_CalcTableSize,
TXT_TableDrawer,
TXT_TableKeyPress,
TXT_TableDestructor,
TXT_TableMousePress,
TXT_TableLayout,
TXT_TableFocused,
};
void TXT_InitTable(txt_table_t *table, int columns)
{
int i;
TXT_InitWidget(table, &txt_table_class);
table->columns = columns;
table->widgets = NULL;
table->num_widgets = 0;
table->selected_x = 0;
table->selected_y = 0;
// Add a strut for each column at the start of the table.
// These are used by the TXT_SetColumnWidths function below:
// the struts are created with widths of 0 each, but this
// function changes them.
for (i=0; i<columns; ++i)
{
TXT_AddWidget(table, TXT_NewStrut(0, 0));
}
}
txt_table_t *TXT_NewTable(int columns)
{
txt_table_t *table;
table = malloc(sizeof(txt_table_t));
TXT_InitTable(table, columns);
return table;
}
// Alternative to TXT_NewTable() that allows a list of widgets to be
// provided in its arguments.
txt_table_t *TXT_MakeTable(int columns, ...)
{
txt_table_t *table;
va_list args;
table = TXT_NewTable(columns);
va_start(args, columns);
for (;;)
{
txt_widget_t *widget;
widget = va_arg(args, txt_widget_t *);
if (widget == NULL)
{
break;
}
TXT_AddWidget(table, widget);
}
va_end(args);
return table;
}
// Create a horizontal table from a list of widgets.
txt_table_t *TXT_NewHorizBox(TXT_UNCAST_ARG(first_widget), ...)
{
TXT_CAST_ARG(txt_widget_t, first_widget);
txt_table_t *result;
va_list args;
int num_args;
// First, find the number of arguments to determine the width of
// the box.
va_start(args, TXT_UNCAST_ARG_NAME(first_widget));
num_args = 1;
for (;;)
{
txt_widget_t *widget;
widget = va_arg(args, txt_widget_t *);
if (widget == NULL)
{
// End of list
break;
}
else
{
++num_args;
}
}
va_end(args);
// Create the table.
result = TXT_NewTable(num_args);
TXT_AddWidget(result, first_widget);
// Go through the list again and add each widget.
va_start(args, TXT_UNCAST_ARG_NAME(first_widget));
for (;;)
{
txt_widget_t *widget;
widget = va_arg(args, txt_widget_t *);
if (widget == NULL)
{
// End of list
break;
}
else
{
TXT_AddWidget(result, widget);
}
}
va_end(args);
return result;
}
// Get the currently-selected widget in a table, recursively searching
// through sub-tables if necessary.
txt_widget_t *TXT_GetSelectedWidget(TXT_UNCAST_ARG(table))
{
TXT_CAST_ARG(txt_table_t, table);
txt_widget_t *result;
int index;
index = table->selected_y * table->columns + table->selected_x;
result = NULL;
if (index >= 0 && index < table->num_widgets)
{
result = table->widgets[index];
if (!IsActualWidget(result))
{
result = NULL;
}
}
if (result != NULL && result->widget_class == &txt_table_class)
{
result = TXT_GetSelectedWidget(result);
}
return result;
}
// Selects a given widget in a table, recursively searching any tables
// within this table. Returns 1 if successful, 0 if unsuccessful.
int TXT_SelectWidget(TXT_UNCAST_ARG(table), TXT_UNCAST_ARG(widget))
{
TXT_CAST_ARG(txt_table_t, table);
TXT_CAST_ARG(txt_widget_t, widget);
int i;
for (i=0; i<table->num_widgets; ++i)
{
if (!IsActualWidget(table->widgets[i]))
{
continue;
}
if (table->widgets[i] == widget)
{
// Found the item! Select it and return.
ChangeSelection(table, i % table->columns, i / table->columns);
return 1;
}
if (table->widgets[i]->widget_class == &txt_table_class)
{
// This item is a subtable. Recursively search this table.
if (TXT_SelectWidget(table->widgets[i], widget))
{
// Found it in the subtable. Select this subtable and return.
ChangeSelection(table, i % table->columns, i / table->columns);
return 1;
}
}
}
// Not found.
return 0;
}
void TXT_SetTableColumns(TXT_UNCAST_ARG(table), int new_columns)
{
TXT_CAST_ARG(txt_table_t, table);
txt_widget_t **new_widgets;
txt_widget_t *widget;
int new_num_widgets;
int i, j, x;
// We need as many full rows as are in the current list, plus the
// remainder from the last row.
new_num_widgets = (table->num_widgets / table->columns) * new_columns
+ (table->num_widgets % table->columns);
new_widgets = calloc(new_num_widgets, sizeof(txt_widget_t *));
// Reset and add one by one from the old table.
new_num_widgets = 0;
for (i = 0; i < table->num_widgets; ++i)
{
widget = table->widgets[i];
x = i % table->columns;
if (x < new_columns)
{
new_widgets[new_num_widgets] = widget;
++new_num_widgets;
}
else if (IsActualWidget(widget))
{
TXT_DestroyWidget(widget);
}
// When we reach the last column of a row, we must pad it out with
// extra widgets to reach the next row.
if (x == table->columns - 1)
{
for (j = table->columns; j < new_columns; ++j)
{
// First row? We need to add struts that are used to apply
// the column widths.
if (i < table->columns)
{
widget = &TXT_NewStrut(0, 0)->widget;
}
else
{
widget = &txt_table_overflow_right;
}
new_widgets[new_num_widgets] = widget;
++new_num_widgets;
}
}
}
free(table->widgets);
table->widgets = new_widgets;
table->num_widgets = new_num_widgets;
table->columns = new_columns;
}
// Sets the widths of columns in a table.
void TXT_SetColumnWidths(TXT_UNCAST_ARG(table), ...)
{
TXT_CAST_ARG(txt_table_t, table);
va_list args;
txt_strut_t *strut;
int i;
int width;
va_start(args, TXT_UNCAST_ARG_NAME(table));
for (i=0; i<table->columns; ++i)
{
width = va_arg(args, int);
strut = (txt_strut_t *) table->widgets[i];
strut->width = width;
}
va_end(args);
}
// Moves the select by at least the given number of characters.
// Currently quietly ignores pagex, as we don't use it.
int TXT_PageTable(TXT_UNCAST_ARG(table), int pagex, int pagey)
{
TXT_CAST_ARG(txt_table_t, table);
unsigned int *column_widths;
unsigned int *row_heights;
int rows;
int changed = 0;
rows = TableRows(table);
row_heights = malloc(sizeof(int) * rows);
column_widths = malloc(sizeof(int) * table->columns);
CalcRowColSizes(table, row_heights, column_widths);
if (pagex)
{
// @todo Jump selection to the left or right as needed
}
if (pagey)
{
int new_x, new_y;
int distance = 0;
int dir;
// What direction are we moving?
if (pagey > 0)
{
dir = 1;
}
else
{
dir = -1;
}
// Move the cursor until the desired distance is reached.
new_y = table->selected_y;
while (new_y >= 0 && new_y < rows)
{
// We are about to travel a distance equal to the height of the row
// we are about to leave.
distance += row_heights[new_y];
// *Now* increment the loop.
new_y += dir;
new_x = FindSelectableColumn(table, new_y, table->selected_x);
if (new_x >= 0)
{
// Found a selectable widget in this column!
// Select it anyway in case we don't find something better.
ChangeSelection(table, new_x, new_y);
changed = 1;
// ...but is it far enough away?
if (distance >= abs(pagey))
{
break;
}
}
}
}
free(row_heights);
free(column_widths);
return changed;
}