1 files changed, 349 insertions, 0 deletions

diff --git a/calendar/gui/e-day-view-layout.c b/calendar/gui/e-day-view-layout.c
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+++ b/calendar/gui/e-day-view-layout.c
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+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+
+/*
+ * Author :
+ *  Damon Chaplin <damon@ximian.com>
+ *
+ * Copyright 2001, Ximian, Inc.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ */
+
+/*
+ * Lays out events for the Day & Work-Week views of the calendar. It is also
+ * used for printing.
+ */
+
+#include <config.h>
+
+#include "e-day-view-layout.h"
+
+static void e_day_view_layout_long_event (EDayViewEvent	  *event,
+					  guint8	  *grid,
+					  gint		   days_shown,
+					  time_t	  *day_starts,
+					  gint		  *rows_in_top_display);
+
+static void e_day_view_layout_day_event (EDayViewEvent    *event,
+					 guint8	          *grid,
+					 guint16	  *group_starts,
+					 gint8	          *cols_per_row,
+					 gint	           rows,
+					 gint	           mins_per_row);
+static void e_day_view_expand_day_event (EDayViewEvent    *event,
+					 guint8	          *grid,
+					 gint8	          *cols_per_row,
+					 gint	           mins_per_row);
+static void e_day_view_recalc_cols_per_row (gint           rows,
+					    gint8	  *cols_per_row,
+					    guint16       *group_starts);
+
+
+void
+e_day_view_layout_long_events (GArray	   *events,
+			       gint	   days_shown,
+			       time_t	  *day_starts,
+			       gint	   *rows_in_top_display)
+{
+	EDayViewEvent *event;
+	gint event_num;
+	guint8 *grid;
+
+	/* This is a temporary 2-d grid which is used to place events.
+	   Each element is 0 if the position is empty, or 1 if occupied.
+	   We allocate the maximum size possible here, assuming that each
+	   event will need its own row. */
+	grid = g_new0 (guint8, events->len * E_DAY_VIEW_MAX_DAYS);
+
+	/* Reset the number of rows in the top display to 0. It will be
+	   updated as events are layed out below. */
+	*rows_in_top_display = 0;
+
+	/* Iterate over the events, finding which days they cover, and putting
+	   them in the first free row available. */
+	for (event_num = 0; event_num < events->len; event_num++) {
+		event = &g_array_index (events, EDayViewEvent, event_num);
+		e_day_view_layout_long_event (event, grid,
+					      days_shown, day_starts,
+					      rows_in_top_display);
+	}
+
+	/* Free the grid. */
+	g_free (grid);
+}
+
+
+static void
+e_day_view_layout_long_event (EDayViewEvent *event,
+			      guint8	   *grid,
+			      gint	    days_shown,
+			      time_t	   *day_starts,		
+			      gint	   *rows_in_top_display)
+{
+	gint start_day, end_day, free_row, day, row;
+
+	event->num_columns = 0;
+
+	if (!e_day_view_find_long_event_days (event,
+					      days_shown, day_starts,
+					      &start_day, &end_day))
+		return;
+
+	/* Try each row until we find a free one. */
+	row = 0;
+	do {
+		free_row = row;
+		for (day = start_day; day <= end_day; day++) {
+			if (grid[row * E_DAY_VIEW_MAX_DAYS + day]) {
+				free_row = -1;
+				break;
+			}
+		}
+		row++;
+	} while (free_row == -1);
+
+	event->start_row_or_col = free_row;
+	event->num_columns = 1;
+
+	/* Mark the cells as full. */
+	for (day = start_day; day <= end_day; day++) {
+		grid[free_row * E_DAY_VIEW_MAX_DAYS + day] = 1;
+	}
+
+	/* Update the number of rows in the top canvas if necessary. */
+	*rows_in_top_display = MAX (*rows_in_top_display, free_row + 1);
+}
+
+
+void
+e_day_view_layout_day_events (GArray	   *events,
+			      gint	    rows,
+			      gint	    mins_per_row,
+			      gint8	   *cols_per_row)
+{
+	EDayViewEvent *event;
+	gint row, event_num;
+	guint8 *grid;
+
+	/* This is a temporary array which keeps track of rows which are
+	   connected. When an appointment spans multiple rows then the number
+	   of columns in each of these rows must be the same (i.e. the maximum
+	   of all of them). Each element in the array corresponds to one row
+	   and contains the index of the first row in the group of connected
+	   rows. */
+	guint16 group_starts[12 * 24];
+
+	/* Reset the cols_per_row array, and initialize the connected rows so
+	   that all rows are not connected - each row is the start of a new
+	   group. */
+	for (row = 0; row < rows; row++) {
+		cols_per_row[row] = 0;
+		group_starts[row] = row;
+	}
+
+	/* This is a temporary 2-d grid which is used to place events.
+	   Each element is 0 if the position is empty, or 1 if occupied. */
+	grid = g_new0 (guint8, rows * E_DAY_VIEW_MAX_COLUMNS);
+
+
+	/* Iterate over the events, finding which rows they cover, and putting
+	   them in the first free column available. Increment the number of
+	   events in each of the rows it covers, and make sure they are all
+	   in one group. */
+	for (event_num = 0; event_num < events->len; event_num++) {
+		event = &g_array_index (events, EDayViewEvent, event_num);
+
+		e_day_view_layout_day_event (event, grid, group_starts,
+					     cols_per_row, rows, mins_per_row);
+	}
+
+	/* Recalculate the number of columns needed in each row. */
+	e_day_view_recalc_cols_per_row (rows, cols_per_row, group_starts);
+
+	/* Iterate over the events again, trying to expand events horizontally
+	   if there is enough space. */
+	for (event_num = 0; event_num < events->len; event_num++) {
+		event = &g_array_index (events, EDayViewEvent, event_num);
+		e_day_view_expand_day_event (event, grid, cols_per_row,
+					     mins_per_row);
+	}
+
+	/* Free the grid. */
+	g_free (grid);
+}
+
+
+/* Finds the first free position to place the event in.
+   Increments the number of events in each of the rows it covers, and makes
+   sure they are all in one group. */
+static void
+e_day_view_layout_day_event (EDayViewEvent *event,
+			     guint8	   *grid,
+			     guint16	   *group_starts,
+			     gint8	   *cols_per_row,
+			     gint	    rows,
+			     gint	    mins_per_row)
+{
+	gint start_row, end_row, free_col, col, row, group_start;
+
+	start_row = event->start_minute / mins_per_row;
+	end_row = (event->end_minute - 1) / mins_per_row;
+
+	event->num_columns = 0;
+
+	/* If the event can't currently be seen, just return. */
+	if (start_row >= rows || end_row < 0)
+		return;
+
+	/* Make sure we don't go outside the visible times. */
+	start_row = CLAMP (start_row, 0, rows - 1);
+	end_row = CLAMP (end_row, 0, rows - 1);
+
+	/* Try each column until we find a free one. */
+	for (col = 0; col < E_DAY_VIEW_MAX_COLUMNS; col++) {
+		free_col = col;
+		for (row = start_row; row <= end_row; row++) {
+			if (grid[row * E_DAY_VIEW_MAX_COLUMNS + col]) {
+				free_col = -1;
+				break;
+			}
+		}
+
+		if (free_col != -1)
+			break;
+	}
+
+	/* If we can't find space for the event, just return. */
+	if (free_col == -1)
+		return;
+
+	/* The event is assigned 1 col initially, but may be expanded later. */
+	event->start_row_or_col = free_col;
+	event->num_columns = 1;
+
+	/* Determine the start index of the group. */
+	group_start = group_starts[start_row];
+
+	/* Increment number of events in each of the rows the event covers.
+	   We use the cols_per_row array for this. It will be sorted out after
+	   all the events have been layed out. Also make sure all the rows that
+	   the event covers are in one group. */
+	for (row = start_row; row <= end_row; row++) {
+		grid[row * E_DAY_VIEW_MAX_COLUMNS + free_col] = 1;
+		cols_per_row[row]++;
+		group_starts[row] = group_start;
+	}
+
+	/* If any following rows should be in the same group, add them. */
+	for (row = end_row + 1; row < rows; row++) {
+		if (group_starts[row] > end_row)
+			break;
+		group_starts[row] = group_start;
+	}
+}
+
+
+/* For each group of rows, find the max number of events in all the
+   rows, and set the number of cols in each of the rows to that. */
+static void
+e_day_view_recalc_cols_per_row (gint      rows,
+				gint8	 *cols_per_row,
+				guint16  *group_starts)
+{
+	gint start_row = 0, row, next_start_row, max_events;
+
+	while (start_row < rows) {
+		max_events = 0;
+		for (row = start_row; row < rows && group_starts[row] == start_row; row++)
+			max_events = MAX (max_events, cols_per_row[row]);
+
+		next_start_row = row;
+
+		for (row = start_row; row < next_start_row; row++)
+			cols_per_row[row] = max_events;
+
+		start_row = next_start_row;
+	}
+}
+
+
+/* Expands the event horizontally to fill any free space. */
+static void
+e_day_view_expand_day_event (EDayViewEvent *event,
+			     guint8	   *grid,
+			     gint8	   *cols_per_row,
+			     gint	    mins_per_row)
+{
+	gint start_row, end_row, col, row;
+	gboolean clashed;
+
+	start_row = event->start_minute / mins_per_row;
+	end_row = (event->end_minute - 1) / mins_per_row;
+
+	/* Try each column until we find a free one. */
+	clashed = FALSE;
+	for (col = event->start_row_or_col + 1; col < cols_per_row[start_row]; col++) {
+		for (row = start_row; row <= end_row; row++) {
+			if (grid[row * E_DAY_VIEW_MAX_COLUMNS + col]) {
+				clashed = TRUE;
+				break;
+			}
+		}
+
+		if (clashed)
+			break;
+
+		event->num_columns++;
+	}
+}
+
+
+/* Find the start and end days for the event. */
+gboolean
+e_day_view_find_long_event_days (EDayViewEvent	*event,
+				 gint		 days_shown,
+				 time_t		*day_starts,		
+				 gint		*start_day_return,
+				 gint		*end_day_return)
+{
+	gint day, start_day, end_day;
+
+	start_day = -1;
+	end_day = -1;
+
+	for (day = 0; day < days_shown; day++) {
+		if (start_day == -1
+		    && event->start < day_starts[day + 1])
+			start_day = day;
+		if (event->end > day_starts[day])
+			end_day = day;
+	}
+
+	/* Sanity check. */
+	if (start_day < 0 || start_day >= days_shown
+	    || end_day < 0 || end_day >= days_shown
+	    || end_day < start_day) {
+		g_warning ("Invalid date range for event");
+		return FALSE;
+	}
+
+	*start_day_return = start_day;
+	*end_day_return = end_day;
+
+	return TRUE;
+}
+
+