1 files changed, 415 insertions, 0 deletions
diff --git a/render/loosen.c b/render/loosen.c
new file mode 100644
index 000000000..91c4056ef
--- /dev/null
+++ b/render/loosen.c
@@ -0,0 +1,415 @@
+/*
+ * Copyright 2008 Adam Blokus <adamblokus@gmail.com>
+ *
+ * This file is part of NetSurf, http://www.netsurf-browser.org/
+ *
+ * NetSurf 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; version 2 of the License.
+ *
+ * NetSurf 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, see <http://www.gnu.org/licenses/>.
+ */
+ 
+#include <stdbool.h>
+#include <assert.h>
+
+#include "content/content.h"
+
+#include "render/box.h"
+#include "render/font.h"
+
+#include "utils/log.h"
+#include "utils/talloc.h"
+
+#define AUTO INT_MIN
+
+
+static bool loosen_text(struct box *text, int width, struct content *content);
+
+static bool loosen_table(struct box *box, int available_width,
+		struct content *content);
+				
+static bool loosen_position_static(struct box *box, int width, int cx,
+		struct content *content);
+
+static bool loosen_shrink_object(struct box *box, int width);
+
+static bool loosen_all_first_pass(struct box *box, int width, int cx,
+		struct content *content);
+static bool loosen_all_second_pass(struct box *box, int width, int cx,
+		struct content *content);
+static bool loosen_all_third_pass(struct box *box, int width, int cx,
+		struct content *content);
+
+/**
+ * Main loosing procedure
+ * \param content Reformated content - talloc memory pool for new boxes
+ * \param layout Root of the loosened box tree
+ * \param width Width the content is intended to fit
+ * \param height Height of a single page - to be taken into consideration for \
+ * 	preventing elements for being cropped at top/bottom edges of pages.
+ * \return true if successful, false otherwise (lack of memory)
+*/
+bool loosen_document_layout(struct content *content, struct box *layout,
+		int width, int height)
+{
+	/* Optional try - if the current layout is not more than xx% too wide,
+	 * maybe we scale the content to preserve the original layout?
+	 */
+
+	if (!loosen_all_first_pass(layout, width, 0, content))
+		return false;
+	layout->min_width = 0;
+	layout->max_width = UNKNOWN_MAX_WIDTH;
+	content_reformat(content, width, 0);
+
+	/*Check if pass 1 was enough - if re-layouting doesn't give 
+	 *us the right width, go on to pass 2. And again - if pass 2 was not
+	 *enough - go on to pass 3
+	 */
+	
+	if (content->width > width) {
+		if (!loosen_all_second_pass(layout, width, 0, content))
+			return false;
+		layout->min_width = 0;
+		layout->max_width = UNKNOWN_MAX_WIDTH;
+		content_reformat(content, width, 0);
+	}
+	
+	if (content->width > width) {
+		if (!loosen_all_third_pass(layout, width, 0, content))
+			return false;
+		layout->min_width = 0;
+		layout->max_width = UNKNOWN_MAX_WIDTH;
+		content_reformat(content, width, 0);
+	}
+	
+	return true;
+}
+
+/** Primarily - break too wide words into pieces.
+ * \param text - the box that contains text to be broken
+ * \param width Width the content is intended to fit
+ * \param content talloc memory pool for new boxes
+ * \return true if successful, false otherwise 
+*/
+bool loosen_text(struct box *text, int width, struct content *content)
+{
+	unsigned int offset;
+	int actual_x;
+	
+	int *breaks;
+	int break_count;
+	
+	int position, i;
+	const struct font_functions *font_func;
+	
+	if (content->type == CONTENT_HTML)
+		font_func = content->data.html.font_func;
+	else
+		return false;
+	
+	if (text->width <= width) {
+		LOG(("loosen_text called unnecessary?"));
+		/*Still - not an error for this function*/
+		return true;
+	}
+	
+	breaks = malloc( sizeof(int) * text->length);
+	if (breaks == NULL)
+		return false;
+	
+ 	break_count = 0;
+	position = 0;
+	
+	while (position < text->length) {
+		font_func->font_position_in_string(text->style,
+				text->text + position,
+				text->length - position,
+				width, &offset, &actual_x);
+		
+		if (offset < text->length - position) {
+			/*Another break*/
+			LOG(("Current text broken at offset %d",
+					position + offset));
+			breaks[break_count++] = position + offset-1;
+		}
+		
+		position += offset;
+	}
+	
+	text->text = talloc_realloc(content, text->text, char,
+			text->length + break_count);
+	
+	i = text->length-1;
+	text->length = text->length + break_count;
+
+	for (; i>=0; i--) {
+		text->text[i + break_count] = text->text[i];
+		if (i == breaks[break_count - 1]) {
+			break_count--;
+			text->text[i + break_count] = ' ';
+		}
+	}
+	
+	free(breaks);
+
+	return true;
+}
+
+/**
+ * Changing table layout and structure to fit the contents width.
+ * In the most extreme case - the table has no influence on the width
+ * (each row is broken into one-cell rows).
+ * \param table - the box that contains table to be broken
+ * \param width Width the content is intended to fit
+ * \param content talloc memory pool for new boxes
+ * \return true if successful, false otherwise 
+ */
+bool loosen_table(struct box *table, int width, struct content *content)
+{
+				 
+	struct box *row_group, *row, *cell, *br, *prev, *inline_container;
+	unsigned int row_sum;
+	bool first_cell_in_row;
+		
+	if (table->min_width <= width)
+		return true;	
+	
+	inline_container = box_create(0, 0, 0, 0, 0, content);
+	inline_container->type = BOX_INLINE_CONTAINER;
+	inline_container->parent = table;
+	inline_container->style = talloc_memdup(content, table->style,
+			sizeof *table->style);
+	
+	prev = NULL;
+	
+	for (row_group = table->children; row_group;
+			row_group = row_group->next) {
+		for (row = row_group->children; row; row = row->next) {
+			
+			for (cell = row->children; cell; cell = cell->next) {
+				cell->type = BOX_INLINE_BLOCK;
+				cell->prev = prev;
+				cell->parent = inline_container;
+				cell->max_width = width;
+				cell->min_width = 0;
+				
+				if (prev!=NULL)
+					prev->next = cell;
+				else
+					inline_container->children = cell;
+					
+				prev = cell;
+			}
+			
+			br = box_create(0, 0, 0, 0, 0, content);
+			br->type = BOX_BR;
+			br->parent = inline_container;
+			br->prev = prev;
+			br->style = talloc_memdup(content, table->style,
+					sizeof *table->style);
+			br->style->clear = CSS_CLEAR_BOTH;
+			
+			if (prev != NULL)
+				prev->next = br;
+			else
+				inline_container->children = br;
+			
+			prev = br;
+		}
+	}
+	inline_container->last = prev;
+	
+	table->type = BOX_BLOCK;
+	table->children = table->last = inline_container;
+	table->col = NULL;
+
+	return true;
+}
+
+
+/**
+ * Change absolute and relative positioned elements into block elements
+ * in case they are positioned to far to the rigth
+ * \param box - the box that should be changed
+ * \param width Width the content is intended to fit
+ * \param cx current x - not yet in use
+ * \param content talloc memory pool for new boxes
+ * \return true if successful, false otherwise 
+ */
+bool loosen_position_static(struct box *box, int width, int cx,
+		struct content *content)
+{
+	assert(box->style);
+
+	if (box->style->position == CSS_POSITION_ABSOLUTE) {	
+	   box->style->position = CSS_POSITION_NOT_SET;
+	}
+	
+	return true;
+}
+		
+/**
+ * Shrink an object (esp. an image) to fit the page-width
+ * \note Not sure wheter it won't be better for images to be cropped
+ * \param box - the box that should be changed
+ * \param width Width the content is intended to fit
+ * \return true if successful, false otherwise 
+*/
+bool loosen_shrink_object(struct box *box, int width)
+{
+	assert(box->object != NULL);
+	
+	box->height = AUTO;
+	box->width = width;
+	
+	if (box->style) {
+		box->style->width.width = CSS_WIDTH_PERCENT;
+		box->style->width.value.percent = 100;
+		box->style->height.height= CSS_HEIGHT_AUTO;
+	}
+	
+	return true;
+}
+
+/**
+ * Pass 1 of loosening - do such obvious changes as: breaking too long words,
+ * moving absolute positioned objects into the visibile scope of width.
+ * \param box - the box that should be changed
+ * \param width Width the content is intended to fit
+ * \param cx current x - not yet in use
+ * \param content talloc memory pool for new boxes
+ * \return true if successful, false otherwise 
+*/
+bool loosen_all_first_pass(struct box *box, int width, int cx,
+		struct content *content)
+{
+	struct box* c;
+	int got_width;
+	int x;
+	
+	for (c = box->children; c ; c = c->next) {
+		x = cx + c->x;
+		if (c->children != NULL)
+			if (!loosen_all_first_pass(c, width, x, content))
+				return false;
+		
+		if (c->style) {
+			if (c->style->position == CSS_POSITION_RELATIVE ||
+					c->style->position == CSS_POSITION_ABSOLUTE )
+				if (!loosen_position_static(c, width, cx, content))
+					return false;
+			if ( c->style->width.width == CSS_WIDTH_LENGTH &&
+					css_len2px(&c->style->width.value.length, c->style) > width)
+				c->style->width.width = CSS_WIDTH_NOT_SET;
+		}
+		
+		if (c->object && c->width > width)
+			if (!loosen_shrink_object(c, width))
+				return false;
+				
+		switch (c->type) {
+			case BOX_TEXT:
+				if (!loosen_text(c, width, content))
+					return false;
+				break;
+		}
+		
+		c->min_width = 0;
+		c->max_width = UNKNOWN_MAX_WIDTH;
+		
+	}
+	
+	return true;
+}
+
+/**
+ * Pass 2 of loosening - break tables
+ * \param box - the box that should be changed
+ * \param width Width the content is intended to fit
+ * \param cx current x - not yet in use
+ * \param content talloc memory pool for new boxes
+ * \return true if successful, false otherwise 
+ */
+bool loosen_all_second_pass(struct box *box, int width, int cx,
+		struct content *content)
+{
+	struct box *c;
+	int got_width;
+	int x;
+	
+	for (c = box->children; c; c = c->next) {
+		x = cx + c->x;
+		if (c->children != NULL)
+			if (!loosen_all_second_pass(c, width, x, content))
+				return false;
+		
+		switch (c->type) {
+			case BOX_TABLE:
+				if (!loosen_table(c, width, content))
+					return false;
+				break;
+		}
+		
+		c->min_width = 0;
+		c->max_width = UNKNOWN_MAX_WIDTH;
+	}	
+	
+	return true;
+}
+
+
+/**
+ * Pass 3 of loosening -zero all margins and paddings
+ * \param box - the box that should be changed
+ * \param width Width the content is intended to fit
+ * \param cx current x - not yet in use
+ * \param content talloc memory pool for new boxes
+ * \return true if successful, false otherwise 
+ */
+bool loosen_all_third_pass(struct box *box, int width, int cx,
+		struct content *content)
+{
+	struct box *c;
+	int got_width;
+	int x;
+	
+	for (c = box->children; c; c = c->next) {
+		x = cx + c->x;
+		if (c->children != NULL)
+			if (!loosen_all_third_pass(c, width, x, content))
+				return false;
+
+		c->padding[LEFT] = c->padding[RIGHT] = 0;
+		c->margin[LEFT] = c->margin[RIGHT] = 0;
+		
+		if (c->style) {
+			c->style->margin[LEFT].margin = CSS_MARGIN_PERCENT;
+			c->style->margin[LEFT].value.percent = 0;
+			
+			c->style->margin[RIGHT].margin = CSS_MARGIN_PERCENT;
+			c->style->margin[RIGHT].value.percent = 0;
+			
+			c->style->padding[LEFT].padding = CSS_PADDING_PERCENT;
+			c->style->padding[LEFT].value.percent = 0; 
+			
+			c->style->padding[RIGHT].padding = CSS_PADDING_PERCENT;
+			c->style->padding[RIGHT].value.percent = 0; 
+			
+		}
+
+		c->min_width = 0;
+		c->max_width = UNKNOWN_MAX_WIDTH;
+		
+	}	
+	
+	return true;
+}
+