public static float Calculate (Rule rule, DOMElement element) {
try {
// Cut unnecessary parts
string value = rule.Value.Split(new[] { "calc(" }, StringSplitOptions.None)[1];
value = value.ToLower();
if (value[value.Length - 1] != ')') return -1f;
else value = value.Substring(0, value.Length - 1);
if (value.Length < 2) return -1f;
// Cut pixel unit
value = Compute(rule, element, value, Unit.Px, false);
foreach (Unit unit in CSSUnits.allUnits) value = Compute(rule, element, value, unit);
if (value == null) {
Console.WriteLine("Calc function isn't correct!");
return -1f;
} else {
return float.Parse(new DataTable().Compute(value, "").ToString().Replace(',', '.'), CultureInfo.InvariantCulture.NumberFormat);
}
} catch (Exception exception) {
Console.WriteLine(exception.Message);
return -1f;
}
}
/// <summary>
// Calculates x times the size of the current font
/// </summary>
public static float EmToPx(Rule rule, DOMElement element)
{
float fontSize = (element.Parent != null) ? element.Parent.Style.Font.Size : 16; // 16 - Document font-size
if (element.Style.Font != null)
{
fontSize = element.Style.Font.Size;
}
return(fontSize * rule.ComputedValue.Value);
}
/// <summary>
/// Calculates pixels from percent
/// </summary>
public static float PercentToPx(Rule rule, DOMElement element)
{
if (rule.Property == "width")
{
float parentWidth = (element.Parent != null) ? element.Parent.ComputedStyle.Size.Width : LayoutEngine.htmlDocument.Width;
return((rule.ComputedValue.ValueBeforeComputing / 100) * parentWidth);
}
else if (rule.Property == "height")
{
float parentHeight = (element.Parent != null) ? element.Parent.Style.Size.Height : LayoutEngine.htmlDocument.Height;
return((rule.ComputedValue.ValueBeforeComputing / 100) * parentHeight);
}
return(0f);
}
public static CSSValue ParseValue(Rule rule, DOMElement element)
{
CSSValue cssValue = new CSSValue();
if (rule.Value.StartsWith("calc("))
{
cssValue.Unit = Unit.CalcFunc;
rule.ComputedValue = cssValue;
return(cssValue);
}
else
{
List <string> array = Regex.Split(rule.Value, @"[^0-9\.]+").Where(c => c != "." && c.Trim() != "").ToList();
if (array.Count > 0 && rule.Value.Length > 2)
{
float value = float.Parse(array[0], CultureInfo.InvariantCulture.NumberFormat);
int startIndex = value.ToString().Length;
string unitType = rule.Value.Substring(startIndex, rule.Value.Length - startIndex).ToLower();
cssValue.Value = value;
foreach (Unit unit in allUnits)
{
string abbreviation = GetUnitAbbreviation(unit);
if (unitType == abbreviation)
{
cssValue.Unit = unit;
}
}
rule.ComputedValue = cssValue;
cssValue.Value = ConvertAnyUnitToPixels(rule, element);
cssValue.ValueBeforeComputing = value;
return(cssValue);
}
}
return(null);
}
public static float ConvertAnyUnitToPixels(Rule rule, DOMElement element)
{
CSSValue cssValue = rule.ComputedValue;
if (cssValue.Unit == Unit.Px)
{
return(cssValue.Value);
}
else if (cssValue.Unit == Unit.Cm)
{
return(CSSUnitsConverter.CmToPX(cssValue.Value));
}
else if (cssValue.Unit == Unit.Mm)
{
return(CSSUnitsConverter.MmToPX(cssValue.Value));
}
else if (cssValue.Unit == Unit.In)
{
return(CSSUnitsConverter.InToPX(cssValue.Value));
}
else if (cssValue.Unit == Unit.Percent)
{
return(CSSUnitsConverter.PercentToPx(rule, element));
}
else if (cssValue.Unit == Unit.Pt)
{
return(CSSUnitsConverter.PtToPX(cssValue.Value));
}
else if (cssValue.Unit == Unit.Em)
{
return(CSSUnitsConverter.EmToPx(rule, element));
}
else if (cssValue.Unit == Unit.Vh)
{
return(CSSUnitsConverter.VhToPx(rule, element));
}
else if (cssValue.Unit == Unit.Vw)
{
return(CSSUnitsConverter.VwToPx(rule, element));
}
return(-1f);
}
private static string Compute (Rule rule, DOMElement element, string calcString, Unit unitType, bool convert = true) {
while (true) {
string unit = CSSUnits.GetUnitAbbreviation(unitType);
int unitStartIndex = calcString.IndexOf(unit);
int unitEndIndex = unitStartIndex + unit.Length;
// If there is no unit
if (unitStartIndex == -1) break;
// Get starting value index
int valueStartIndex = GetStartIndex(calcString, unitStartIndex);
if (valueStartIndex == unitStartIndex) return null;
// Get and parse value
string value = calcString.Substring(valueStartIndex, unitStartIndex - valueStartIndex);
float parsedValue = float.Parse(value, CultureInfo.InvariantCulture.NumberFormat);
// Compute the value
if (convert) {
rule.ComputedValue.Unit = unitType;
rule.ComputedValue.ValueBeforeComputing = parsedValue;
rule.ComputedValue.Value = parsedValue;
}
float computedValue = (convert) ? CSSUnits.ConvertAnyUnitToPixels(rule, element) : parsedValue;
// Replace string with computed value
StringBuilder stringBuilder = new StringBuilder(calcString);
stringBuilder.Remove(valueStartIndex, unitStartIndex - valueStartIndex + unit.Length);
stringBuilder.Insert(valueStartIndex, computedValue.ToString().Replace(',', '.'));
calcString = stringBuilder.ToString();
}
return calcString;
}
private static void SetPositions(List <DOMElement> elements)
{
foreach (DOMElement element in elements)
{
if (elements.IndexOf(element) > 0)
{
DOMElement prevElement = elements[elements.IndexOf(element) - 1];
if (element.Style.Display == Display.InlineBlock || element.Style.Display == Display.TableCell)
{
element.ComputedStyle.Position.Y = prevElement.ComputedStyle.Position.Y + element.ComputedStyle.Padding.Top;
element.ComputedStyle.Position.X = 0;
if (prevElement.Style.Display == element.Style.Display)
{
element.ComputedStyle.Position.X += prevElement.ComputedStyle.Position.X + prevElement.ComputedStyle.Size.Width;
}
else
{
element.ComputedStyle.Position.Y += prevElement.ComputedStyle.Size.Height + prevElement.Style.Margin.Bottom + element.Style.Margin.Top;
}
element.ComputedStyle.Position.X += (prevElement.Style.Margin.Right >= element.Style.Margin.Left)
? prevElement.Style.Margin.Right
: element.Style.Margin.Left;
}
else if (element.Style.Display == Display.Block || element.Style.Display == Display.TableRow || element.Style.Display == Display.Table)
{
element.ComputedStyle.Position.Y = prevElement.ComputedStyle.Position.Y + prevElement.ComputedStyle.Size.Height;
if (element.Parent != null)
{
element.ComputedStyle.Position.X = element.Parent.ComputedStyle.Position.X + element.ComputedStyle.Padding.Left;
}
element.ComputedStyle.Position.Y += (prevElement.Style.Margin.Bottom >= element.Style.Margin.Top)
? prevElement.Style.Margin.Bottom
: element.Style.Margin.Top;
element.ComputedStyle.Position.X += (prevElement.Style.Margin.Right >= element.Style.Margin.Left)
? prevElement.Style.Margin.Right
: element.Style.Margin.Left;
}
if (prevElement.Style.Display == Display.None)
{
element.ComputedStyle.Position.X = prevElement.ComputedStyle.Position.X;
element.ComputedStyle.Position.Y = prevElement.ComputedStyle.Position.Y;
}
}
else
{
element.ComputedStyle.Position.Y = element.Style.Margin.Top;
element.ComputedStyle.Position.X = element.Style.Margin.Left;
if (element.Parent != null)
{
element.ComputedStyle.Position.Y += element.Parent.ComputedStyle.Position.Y;
element.ComputedStyle.Position.X += element.Parent.ComputedStyle.Position.X;
}
element.ComputedStyle.Position.Y += element.ComputedStyle.Padding.Top;
element.ComputedStyle.Position.X += element.ComputedStyle.Padding.Left;
}
if (element.Children.Count > 0)
{
SetPositions(element.Children);
}
}
}
private static List <DOMElement> GetDOMTree(List <Element> elements)
{
List <DOMElement> domElements = new List <DOMElement>();
List <DOMElement> domTree = new List <DOMElement>();
for (int x = 0; x < elements.Count; x++)
{
// Initialize an DOMElement.
DOMElement domElement = new DOMElement()
{
Level = elements[x].Level
};
if (elements[x].Type == ElementType.Text)
{
domElement.Content = elements[x].Content;
domElement.Type = DOMElementType.Text;
}
else if (elements[x].Type == ElementType.Tag)
{
domElement.Type = DOMElementType.Normal;
domElement.Tag = elements[x].Tag;
}
bool canBeProcessed = false;
if (elements[x].Type == ElementType.Text)
{
canBeProcessed = true;
}
else if (elements[x].Type == ElementType.Tag)
{
canBeProcessed = elements[x].Tag.Type == TagType.Opening || elements[x].Tag.Type == TagType.SelfClosing;
}
if (elements[x].Level != 0)
{
if (canBeProcessed)
{
DOMElement parent = null;
// Get parent of current DOMElement.
for (int y = domElements.Count - 1; y >= 0; y--)
{
if (domElements[y].Level == domElement.Level - 1)
{
parent = domElements[y];
break;
}
}
if (parent != null)
{
// Set parent of current DOMElement.
domElement.Parent = parent;
// Add current DOMElement to parent's children list.
parent.Children.Add(domElement);
}
}
}
else
{
if (canBeProcessed)
{
// Add DOMElements to domTree that have only level 0.
domTree.Add(domElement);
}
}
domElements.Add(domElement);
}
return(domTree);
}
/// <summary>
// Calculates x percent of viewport width
/// </summary>
public static float VwToPx(Rule rule, DOMElement element)
{
return(rule.ComputedValue.Value / 100 * LayoutEngine.htmlDocument.getViewport().Width);
}