Do some cleanup; now we pass a struct with the layout algorithm's state

1998-10-08  Federico Mena Quintero  <federico@nuclecu.unam.mx>

	* layout.c: Do some cleanup; now we pass a struct with the layout
	algorithm's state instead of passing a trillion parameters around.

	* gncal-full-day.c (layout_children): Use the new generic layout
	engine.
	(child_compare): Sort keys are start time then end time, not just
	start time.  This produces somewhat nicer results for the layout
	algorithm.

	The new layout code uses a partition of the time range occupied by
	the events, rather than using a fixed time granularity.  This is
	better since the different parts of the program that use the
	layout module will have different semantics regarding snapping the
	event bounds to a fixed "time grid".

svn path=/trunk/; revision=434

4 files changed, 148 insertions, 200 deletions

diff --git a/calendar/gui/gncal-full-day.c b/calendar/gui/gncal-full-day.c
index 6acc8ca16b..402c19acee 100644
--- a/calendar/gui/gncal-full-day.c
+++ b/calendar/gui/gncal-full-day.c
@@ -12,6 +12,7 @@
 #include "eventedit.h"
 #include "gncal-full-day.h"
 #include "view-utils.h"
+#include "layout.h"
 #include "main.h"
 #include "popup-menu.h"
 
@@ -46,11 +47,6 @@ typedef struct {
 	time_t      start, end;
 } Child;
 
-struct layout_row {
-	int  intersections;
-	int *slots;
-};
-
 struct drag_info {
 	enum {
 		DRAG_NONE,
@@ -778,145 +774,64 @@ calc_labels_width (GncalFullDay *fullday)
 	return max_w;
 }
 
-#define MAX_CHILDREN_ON_ROW 32
-
-#define xy(a,x,y) (a[((y) * MAX_CHILDREN_ON_ROW) + (x)])
-
-static int
-range_empty (char *array, int slot, int lower, int count)
-{
-	int i;
-
-	for (i = 0; i < count; i++)
-		if (xy (array, slot, lower+i) != 0)
-			return 0;
-	return 1;
-}
-
+/* Used with layout_events(), takes in a list element and returns the start and end times for the
+ * event corresponding to that element.
+ */
 static void
-range_allocate (char *array, int slot, int lower, int count, int val)
+child_layout_query_func (GList *event, time_t *start, time_t *end)
 {
-	int i;
-
-	for (i = 0; i < count; i++)
-		xy (array, slot, lower+i) = val;
-}
-
-static int
-can_expand (char *array, int *allocations, int top_slot, int val, int lower, int count)
-{
-	int slot, i;
-	int cols = 0;
-
-	for (slot = allocations [val] + 1; slot < top_slot; slot++){
-		for (i = 0; i < count; i++)
-			if (xy (array, slot, lower+i))
-				return cols;
-		cols++;
-	}
-	return cols;
-}
+	Child *child;
 
-static void
-expand_space (char *array, int *allocations, int val, int lower, int count, int cols)
-{
-	int j, i, slot;
+	child = event->data;
 
-	for (i = 0; i < count; i++){
-		slot = allocations [val] + 1;
-		for (j = 0; j < cols; j++)
-			xy (array, slot + j, lower+i) = val;
-	}
+	*start = child->start;
+	*end = child->end;
 }
 
+/* Takes the list of children in the full day view and lays them out nicely without overlapping.
+ * Basically it calls the layout_events() function in layout.c and resizes the fullday's children.
+ */
 static void
 layout_children (GncalFullDay *fullday)
 {
 	GtkWidget *widget;
-	int lines = (24 * 60) / fullday->interval;
-	char *array = g_malloc0 (sizeof (char) * lines * MAX_CHILDREN_ON_ROW);
 	GList *children;
-	int val, slot;
-	int  *allocations, *columns;
-	int top_slot = 0;
-	int left_x, cols;
-	int pixels_per_col, extra_pixels, extra, usable_pixels;
-	int child_count;
-	
+	Child *child;
+	int num_slots;
+	int *allocations;
+	int *slots;
+	int left_x;
+	int usable_pixels, pixels_per_col, extra_pixels;
+	int i;
+
 	if (!fullday->children)
 		return;
-	
-	/* initial allocation */
-	child_count = g_list_length (fullday->children) + 2;
-	allocations = g_malloc0 (sizeof (int) * child_count);
-	columns     = g_malloc0 (sizeof (int) * child_count);
-	val = 1;
-	for (children = fullday->children; children; children = children->next, val++){
-		Child *child = children->data;
-
-		allocations [val] = 0;
-		columns     [val] = 1;
-		for (slot = 0; slot < MAX_CHILDREN_ON_ROW; slot++){
-			if (range_empty (array, slot, child->lower_row, child->rows_used)){
-				/*
-				  printf ("Child %d uses %d-%d allocates slot=%d\n", val, child->lower_row,
-				  child->lower_row + child->rows_used, slot);
-				*/
-				
-				range_allocate (array, slot, child->lower_row, child->rows_used, val);
-				allocations [val] = slot;
-				columns     [val] = 1;
-				if (slot+1 > top_slot)
-					top_slot = slot+1;
-				break;
-			}
-		}
-	}
-#if DEBUGME
-	for (val = 0; val < 48; val++){
-		int j;
-		
-		printf ("%d: ", val);
-		for (j = 0; j < top_slot; j++){
-			printf (" %d", xy (array, j, val));
-		}
-		printf ("\n");
-	}
-#endif
-	/* Expand */
-	val = 1;
-	for (children = fullday->children; children; children = children->next, val++){
-		Child *child = children->data;
-		
-		cols = can_expand (array, allocations, top_slot, val, child->lower_row, child->rows_used);
-		/* printf ("Can expand regresa: %d\n", cols); */
-		if (!cols)
-			continue;
-		expand_space (array, allocations, val, child->lower_row, child->rows_used, cols);
-		columns [val] += cols;
-	}
 
-	/* Assign the spaces */
+	layout_events (fullday->children, child_layout_query_func, &num_slots, &allocations, &slots);
+
+	/* Set the size and position of each child */
+
 	widget = GTK_WIDGET (fullday);
 	left_x = 2 * (widget->style->klass->xthickness + TEXT_BORDER) + calc_labels_width (fullday);
 
-	usable_pixels  = widget->allocation.width-left_x - widget->style->klass->xthickness;
-	pixels_per_col = usable_pixels / top_slot;
-	extra_pixels   = usable_pixels % top_slot;
-	
-	val = 1;
-	for (children = fullday->children; children; children = children->next, val++){
-		Child *child = children->data;
-		
-		child->x     = left_x + pixels_per_col * allocations [val];
-		extra = (allocations [val] + columns [val] == top_slot) ? extra_pixels : 0;
-		child->width = pixels_per_col * columns [val] + extra;
-		child_set_size (child);
+	usable_pixels = widget->allocation.width - left_x - widget->style->klass->xthickness;
+	pixels_per_col = usable_pixels / num_slots;
+	extra_pixels = usable_pixels % num_slots;
+
+	for (children = fullday->children, i = 0; children; children = children->next, i++) {
+		child = children->data;
 
-		/* printf ("Setting child %d to %d for %d pixels\n", val, allocations [val], columns [val]); */
+		child->x = left_x + pixels_per_col * allocations[i];
+		child->width = pixels_per_col * slots[i];
+
+		if ((allocations[i] + slots[i]) == num_slots)
+			child->width += extra_pixels;
+
+		child_set_size (child);
 	}
+
 	g_free (allocations);
-	g_free (columns);
+	g_free (slots);
 }
 
 guint
@@ -2118,13 +2033,17 @@ gncal_full_day_forall (GtkContainer *container, gboolean include_internals, GtkC
 }
 
 static gint
-child_compare_by_start (gconstpointer a, gconstpointer b)
+child_compare (gconstpointer a, gconstpointer b)
 {
 	const Child *ca = a;
 	const Child *cb = b;
 	time_t diff;
 	
 	diff = ca->start - cb->start;
+
+	if (diff == 0)
+		diff = cb->end - ca->end;
+
 	return (diff < 0) ? -1 : (diff > 0) ? 1 : 0;
 }
 
@@ -2135,7 +2054,7 @@ fullday_add_children (iCalObject *obj, time_t start, time_t end, void *c)
 	Child *child;
 	
 	child = child_new (fullday, start, end, obj);
-	fullday->children = g_list_insert_sorted (fullday->children, child, child_compare_by_start);
+	fullday->children = g_list_insert_sorted (fullday->children, child, child_compare);
 
 	return 1;
 }
diff --git a/calendar/gui/layout.c b/calendar/gui/layout.c
index 03fac94cc6..f97f0d5ffd 100644
--- a/calendar/gui/layout.c
+++ b/calendar/gui/layout.c
@@ -6,9 +6,25 @@
  *          Federico Mena <federico@nuclecu.unam.mx>
  */
 
+#include <config.h>
+#include <stdlib.h>
 #include "layout.h"
 
 
+/* This structure is used to pass around layout information among the internal layout functions */
+struct layout_info {
+	GList *events;			/* List of events from client */
+	int num_events;			/* The number of events (length of the list) */
+	LayoutQueryTimeFunc func;	/* Function to convert a list item to a start/end time pair */
+	int num_rows;			/* Size of the time partition */
+	time_t *partition;		/* The time partition containing start and end time values */
+	int *array;			/* Working array of free and allocated time slots */
+	int *allocations;		/* Returned array of slot allocations */
+	int *slots;			/* Returned array of slots used */
+	int num_slots;			/* Number of slots used */
+};
+
+
 /* This defines the maximum number of events to overlap per row.  More than that number of events
  * will not be displayed.  This is not ideal, so sue me.
  */
@@ -35,37 +51,35 @@ compare_time_t (const void *a, const void *b)
 /* Builds a partition of the time range occupied by the events in the list.  It returns an array
  * with the times that define the partition and the number of items in the partition.
  */
-static time_t *
-build_partition (GList *events, int num_events, int *num_rows)
+static void
+build_partition (struct layout_info *li)
 {
 	time_t *rows, *p, *q;
 	GList *list;
-	CalendarObject *co;
 	int i, unique_vals;
 
 	/* This is the maximum number of rows we would need */
 
-	*num_rows = num_events * 2;
+	li->num_rows = li->num_events * 2;
 
 	/* Fill the rows with the times */
 
-	rows = g_new (time_t, *num_rows);
+	rows = g_new (time_t, li->num_rows);
 
-	for (list = events, p = rows; list; list = list->next) {
-		co = list->data;
-		*p++ = co->ev_start;
-		*p++ = co->ev_end;
+	for (list = li->events, p = rows; list; list = list->next) {
+		(* li->func) (list, &p[0], &p[1]);
+		p += 2;
 	}
 
 	/* Do a sort | uniq on the array */
 
-	qsort (rows, *num_rows, sizeof (time_t), compare_time_t);
+	qsort (rows, li->num_rows, sizeof (time_t), compare_time_t);
 
 	p = rows;
 	q = rows + 1;
 	unique_vals = 1;
 
-	for (i = 1; i < *num_rows; i++, q++)
+	for (i = 1; i < li->num_rows; i++, q++)
 		if (*q != *p) {
 			unique_vals++;
 			p++;
@@ -74,33 +88,33 @@ build_partition (GList *events, int num_events, int *num_rows)
 
 	/* Return the number of unique values in the partition and the partition array itself */
 
-	*num_rows = unique_vals;
-	return rows;
+	li->num_rows = unique_vals;
+	li->partition = rows;
 }
 
 /* Returns the index of the element in the partition that corresponds to the specified time */
 int
-find_index (time_t *partition, time_t t)
+find_index (struct layout_info *li, time_t t)
 {
 	int i;
 
 	for (i = 0; ; i++)
-		if (partition[i] == t)
+		if (li->partition[i] == t)
 			return i;
 }
 
-#define xy(slot_array, x, y) slot_array[(y * MAX_EVENTS_PER_ROW) + (x)]
+#define xy(li, x, y) li->array[(y * MAX_EVENTS_PER_ROW) + (x)]
 
 /* Checks that all the cells in the slot array at the specified slot column are free to use by an
  * event that has the specified range.
  */
 static int
-range_is_empty (time_t *partition, int *slot_array, int slot, time_t start, time_t end)
+range_is_empty (struct layout_info *li, int slot, time_t start, time_t end)
 {
 	int i;
 
-	for (i = find_index (partition, start); partition[i] < end; i++)
-		if (xy (slot_array, slot, i) != -1)
+	for (i = find_index (li, start); li->partition[i] < end; i++)
+		if (xy (li, slot, i) != -1)
 			return FALSE;
 
 	return TRUE;
@@ -108,43 +122,44 @@ range_is_empty (time_t *partition, int *slot_array, int slot, time_t start, time
 
 /* Allocates a time in the slot array for the specified event's index */
 static void
-range_allocate (time_t *partition, int *slot_array, int slot, time_t start, time_t end, int ev_num)
+range_allocate (struct layout_info *li, int slot, time_t start, time_t end, int ev_num)
 {
 	int i;
 
-	for (i = find_index (partition, start); partition[i] < end; i++)
-		xy (slot_array, slot, i) = ev_num;
+	for (i = find_index (li, start); li->partition[i] < end; i++)
+		xy (li, slot, i) = ev_num;
 }
 
 /* Performs the initial allocation of slots for events.  Each event gets one column; they will be
  * expanded in a later stage.  Returns the number of columns used.
  */
-static int
-initial_allocate (GList *events, time_t *partition, int *slot_array, int *allocations, int *columns_used)
+static void
+initial_allocate (struct layout_info *li)
 {
-	CalendarObject *co;
+	GList *events;
 	int i;
 	int slot;
 	int num_slots;
+	time_t start, end;
 
 	num_slots = 0;
 
-	for (i = 0; events; events = events->next, i++) {
-		co = events->data;
+	for (i = 0, events = li->events; events; events = events->next, i++) {
+		(* li->func) (events, &start, &end);
 
 		/* Start with no allocation, no columns */
 
-		allocations[i] = -1;
-		columns_used[i] = 0;
+		li->allocations[i] = -1;
+		li->slots[i] = 0;
 
 		/* Find a free column for the event */
 
 		for (slot = 0; slot < MAX_EVENTS_PER_ROW; slot++)
-			if (range_is_empty (partition, slot_array, slot, co->ev_start, co->ev_end)) {
-				range_allocate (partition, slot_array, slot, co->ev_start, co->ev_end, i);
+			if (range_is_empty (li, slot, start, end)) {
+				range_allocate (li, slot, start, end, i);
 
-				allocations[i] = slot;
-				columns_used[i] = 1;
+				li->allocations[i] = slot;
+				li->slots[i] = 1;
 
 				if ((slot + 1) > num_slots)
 					num_slots = slot + 1;
@@ -153,13 +168,12 @@ initial_allocate (GList *events, time_t *partition, int *slot_array, int *alloca
 			}
 	}
 
-	return num_slots;
+	li->num_slots = num_slots;
 }
 
 /* Returns the maximum number of columns that an event can expanded by in the slot array */
 static int
-columns_to_expand (time_t *partition, int *slot_array, int *allocations, int num_slots, int ev_num,
-		   time_t start, time_t end)
+columns_to_expand (struct layout_info *li, int ev_num, time_t start, time_t end)
 {
 	int cols;
 	int slot;
@@ -168,11 +182,11 @@ columns_to_expand (time_t *partition, int *slot_array, int *allocations, int num
 
 	cols = 0;
 
-	i_start = find_index (partition, start);
+	i_start = find_index (li, start);
 
-	for (slot = allocations[ev_num] + 1; slot < num_slots; slot++) {
-		for (i = i_start; partition[i] < end; i++)
-			if (xy (slot_array, slot, i) != -1)
+	for (slot = li->allocations[ev_num] + 1; slot < li->num_slots; slot++) {
+		for (i = i_start; li->partition[i] < end; i++)
+			if (xy (li, slot, i) != -1)
 				return cols;
 
 		cols++;
@@ -181,18 +195,18 @@ columns_to_expand (time_t *partition, int *slot_array, int *allocations, int num
 	return cols;
 }
 
-/* Expands an event to occupy the specified number of columns */
+/* Expands an event by the specified number of columns */
 static void
-do_expansion (time_t *partition, int *slot_array, int *allocations, int ev_num, time_t start, time_t end, int num_cols)
+do_expansion (struct layout_info *li, int ev_num, time_t start, time_t end, int num_cols)
 {
 	int i, j;
 	int slot;
 
-	for (i = find_index (partition, start); partition[i] < end; i++) {
-		slot = allocations[ev_num] + 1;
+	for (i = find_index (li, start); li->partition[i] < end; i++) {
+		slot = li->allocations[ev_num] + 1;
 
 		for (j = 0; j < num_cols; j++)
-			xy (slot_array, slot + j, i) = ev_num;
+			xy (li, slot + j, i) = ev_num;
 	}
 }
 
@@ -200,33 +214,31 @@ do_expansion (time_t *partition, int *slot_array, int *allocations, int ev_num,
  * pass of the layout algorithm.
  */
 static void
-expand_events (GList *events, time_t *partition, int *slot_array, int num_slots, int *allocations, int *columns_used)
+expand_events (struct layout_info *li)
 {
+	GList *events;
+	time_t start, end;
 	int i;
-	CalendarObject *co;
 	int cols;
 
-	for (i = 0; events; events = events->next, i++) {
-		co = events->data;
+	for (i = 0, events = li->events; events; events = events->next, i++) {
+		(* li->func) (events, &start, &end);
 
-		cols = columns_to_expand (partition, slot_array, allocations, num_slots, i, co->ev_start, co->ev_end);
+		cols = columns_to_expand (li, i, start, end);
 
 		if (cols == 0)
 			continue; /* We can't expand this event */
 
-		do_expansion (partition, slot_array, allocations, i, co->ev_start, co->ev_end, cols);
+		do_expansion (li, i, start, end, cols);
 
-		columns_used[i] += cols;
+		li->slots[i] += cols;
 	}
 }
 
 void
-layout_events (GList *events, int *num_slots, int **allocations, int **slots)
+layout_events (GList *events, LayoutQueryTimeFunc func, int *num_slots, int **allocations, int **slots)
 {
-	time_t *time_partition;
-	int *slot_array;
-	int num_events;
-	int num_rows;
+	struct layout_info li;
 	int i;
 
 	g_return_if_fail (num_slots != NULL);
@@ -241,28 +253,33 @@ layout_events (GList *events, int *num_slots, int **allocations, int **slots)
 		return;
 	}
 
-	num_events = g_list_length (events);
+	li.events = events;
+	li.num_events = g_list_length (events);
+	li.func = func;
 
 	/* Build the partition of the time range, and then build the array of slots */
 
-	time_partition = build_partition (events, num_events, &num_rows);
+	build_partition (&li);
 
-	slot_array = g_new (int, num_rows * MAX_EVENTS_PER_ROW);
-	for (i = 0; i < (num_rows * MAX_EVENTS_PER_ROW); i++)
-		slot_array[i] = -1; /* This is our 'empty' value */
+	li.array = g_new (int, li.num_rows * MAX_EVENTS_PER_ROW);
+	for (i = 0; i < (li.num_rows * MAX_EVENTS_PER_ROW); i++)
+		li.array[i] = -1; /* This is our 'empty' value */
 
 	/* Build the arrays for allocations and columns used */
 
-	*allocations = g_new (int, num_events);
-	*slots = g_new (int, num_events);
+	li.allocations = g_new (int, li.num_events);
+	li.slots = g_new (int, li.num_events);
 
-	/* Perform initial allocation -- each event gets one column */
+	/* Perform initial allocation and then expand the events to as many slots as they can occupy */
 
-	*num_slots = initial_allocate (events, time_partition, slot_array, *allocations, *slots);
+	initial_allocate (&li);
+	expand_events (&li);
 
-	/* Expand the events to as many columns as possible */
+	/* Clean up and return values */
 
-	expand_events (events, time_partition, slot_array, *num_slots, *allocations, *slots);
+	g_free (li.array);
 
-	g_free (slot_array);
+	*num_slots = li.num_slots;
+	*allocations = li.allocations;
+	*slots = li.slots;
 }
diff --git a/calendar/gui/layout.h b/calendar/gui/layout.h
index b87cf7e36b..734b720b8b 100644
--- a/calendar/gui/layout.h
+++ b/calendar/gui/layout.h
@@ -9,17 +9,29 @@
 #ifndef LAYOUT_H
 #define LAYOUT_H
 
-#include "calendar.h"
+#include <glib.h>
+#include <time.h>
 
 
-/* This is the main layout function for overlapping events.  You pass in a list of CalendarObject
- * structures and it will calculate a nice non-overlapping layout for them.
+/* Functions of this type must translate the list item into two time_t values for the start and end
+ * of an event.
+ */
+typedef void (* LayoutQueryTimeFunc) (GList *event, time_t *start, time_t *end);
+
+
+/* This is the main layout function for overlapping events.  You pass in a list of (presumably)
+ * events and a function that should take a list element and return the start and end times for the
+ * event corresponding to that list element.
  *
  * It returns the number of slots ("columns") that you need to take into account when actually
  * painting the events, the array of the first slot index that each event occupies, and the array of
  * number of slots that each event occupies.  You have to free both arrays.
+ *
+ * You will get somewhat better-looking results if the list of events is sorted by using the start
+ * time as the primary sort key and the end time as the secondary sort key -- so that "longer"
+ * events go first in the list.
  */
-void layout_events (GList *events, int *num_slots, int **allocations, int **slots);
+void layout_events (GList *events, LayoutQueryTimeFunc func, int *num_slots, int **allocations, int **slots);
 
 
 #endif
diff --git a/calendar/gui/quick-view.c b/calendar/gui/quick-view.c
index 62cb433447..9f647841cb 100644
--- a/calendar/gui/quick-view.c
+++ b/calendar/gui/quick-view.c
@@ -194,7 +194,7 @@ quick_view_new (GnomeCalendar *calendar, char *title, GList *event_list)
 	/* Create base widgets for the popup window */
 
 	w = gtk_frame_new (NULL);
-	gtk_frame_set_shadow_type (GTK_FRAME (w), GTK_SHADOW_OUT);
+	gtk_frame_set_shadow_type (GTK_FRAME (w), GTK_SHADOW_ETCHED_OUT);
 	gtk_container_add (GTK_CONTAINER (qv), w);
 
 	vbox = gtk_vbox_new (FALSE, 0);