private Button(Game game, Vector2 position, Texture2D texture, UIElement parent)
: base(game, null, null, texture, new Vector2?(position), texture.Width, texture.Height, parent)
{
}
public Block(Game game, UIElement parent, Vector2 position, int width, int height)
: base(game, null, null, null, new Vector2?(position), width, height, parent)
{
}
public Button(Game game, Vector2 position, UIElement parent)
: this(game, position, game.Content.Load<Texture2D>("Button"), parent)
{
// Empty.
}
/// <summary>
/// Computes a relative position for a child element.
/// </summary>
/// <remarks>
/// The child will be centered horizontally and the top edge of the child
/// will be atthe specified offset from the top edge of the parent.
/// </remarks>
/// <param name="verticalOffset">Desired offset from top edge of the parent in pixels.</param>
/// <param name="childHeight">Height of child in pixels.</param>
/// <param name="parent">The containing UIElement.</param>
/// <returns>A Vector2 containing the computed center relative position.</returns>
public static Vector2 CenterHorizontal(int verticalOffset, float childHeight, UIElement parent)
{
float y = (verticalOffset + (childHeight / 2f)) / parent.Height - 0.5f;
return new Vector2(0.0f, y);
}
/// <summary>
/// Adds a child to this UIElement.
/// </summary>
/// <remarks>Maintain children in LayerDepth order to ensure proper hit testing.</remarks>
/// <param name="child"></param>
public void AddChild(UIElement child)
{
// Require that the child have been created with this element as its parent.
Debug.Assert(child.Parent == this);
if (!children.Contains(child))
{
children.Add(child);
SortChildrenByLayerDepth();
}
}
/// <summary>
/// Private contructor invoked by overloaded base contructors to build the UIElement.
/// </summary>
/// <param name="game"></param>
/// <param name="controller"></param>
/// <param name="textureFile"></param>
/// <param name="texture"></param>
/// <param name="position">Position of the UIElement (relative or screen coordinates)</param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="parent"></param>
protected UIElement(Game game,
UIController controller,
string textureFile, Texture2D texture,
Vector2? position,
int width, int height,
UIElement parent)
: base(game)
{
// Should only set one or the other, not both.
Debug.Assert(textureFile == null || texture == null);
this.controller = controller;
this.textureSourceFile = textureFile;
this.texture = texture;
this.width = width;
this.height = height;
this.parent = parent;
instanceCount++;
Name = "UIElement " + instanceCount.ToString(CultureInfo.InvariantCulture);
if (parent != null)
{
// Inherit some properties from the parent (containing) UIElement.
currentOrientation = parent.currentOrientation;
screenTransform = parent.ScreenTransform;
spriteBlendMode = parent.SpriteBlendMode;
spriteSortMode = parent.spriteSortMode;
SaveStateMode = parent.SaveStateMode;
// Draw children in front of parents.
layerDepth = parent.layerDepth * 0.9f;
// Position is a relative to parent's Center.
if (position != null)
{
relativePosition = Vector2.Clamp(position.Value,
new Vector2(-0.5f, -0.5f),
new Vector2(0.5f, 0.5f));
Vector2 center = parent.Center;
float x = center.X + relativePosition.X * parent.Width;
float y = center.Y + relativePosition.Y * parent.Height;
Center = new Vector2(x, y);
}
// Add this to parent's liest of children.
parent.AddChild(this);
}
else
{
// Position is in screen coordinates.
if (position != null)
{
Center = position.Value;
}
}
}
/// <summary>
/// Base constructor for UIElement. Only derived classes may call the base constructor.
/// </summary>
/// <param name="parent"></param>
/// <param name="position"></param>
/// <param name="width"></param>
/// <param name="height"></param>
protected UIElement(UIElement parent, Vector2 position, int width, int height)
: this(parent.Game, parent.Controller, (string) null, (Texture2D) null,
position, width, height, parent)
{
// Empty.
}
/// <summary>
/// Base constructor for UIElement. Only derived classes may call the base constructor.
/// </summary>
/// <param name="game"></param>
/// <param name="controller"></param>
/// <param name="position"></param>
/// <param name="width"></param>
/// <param name="height"></param>
/// <param name="parent"></param>
protected UIElement(Game game,
UIController controller,
Vector2? position,
int width, int height,
UIElement parent)
: this(game, controller, null, null, position, width, height, parent)
{
// Empty.
}
/// <summary>
/// Removes a child from this UIElements list of children.
/// </summary>
/// <param name="child"></param>
public void RemoveChild(UIElement child)
{
children.Remove(child);
// Assumption: removing an element from a list does not alter the order of other elements.
}
/// <summary>
/// Finds the layerDepth of the front-most element starting at node.
/// </summary>
/// <param name="node">UIElement node to begin search.</param>
/// <returns>The minimum layerDepth for all elements below node.</returns>
public float MinimumLayerDepth(UIElement node)
{
float minimum = node.LayerDepth;
foreach (UIElement child in node.children)
{
float newMininum = MinimumLayerDepth(child);
if (newMininum < minimum) {
minimum = newMininum;
}
}
return minimum;
}