/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"
#include "nsIVariant.idl"

interface nsIDOMWindow;
interface nsIDOMElement;
interface nsIDOMHTMLElement;
interface nsIDOMHTMLImageElement;
interface nsIDOMHTMLCanvasElement;
interface nsIDOMXULElement;

[scriptable, uuid(bbb20a59-524e-4662-981e-5e142814b20c)]
interface nsIDOMCanvasGradient : nsISupports
{
  void addColorStop(in float offset, in DOMString color);
};

[scriptable, uuid(21dea65c-5c08-4eb1-ac82-81fe95be77b8)]
interface nsIDOMCanvasPattern : nsISupports
{
};

[scriptable, uuid(2d01715c-ec7d-424a-ab85-e0fd70c8665c)]
interface nsIDOMTextMetrics : nsISupports
{
  readonly attribute float width;
};

[scriptable, builtinclass, uuid(1ea11207-b3e3-4ffc-a256-bf5c7011e806)]
interface nsIDOMImageData : nsISupports
{
  readonly attribute unsigned long width;
  readonly attribute unsigned long height;
  [implicit_jscontext] readonly attribute jsval data;
};

[scriptable, uuid(c835c768-2dcc-461c-82f5-3653710d2942)]
interface nsIDOMCanvasRenderingContext2D : nsISupports
{
  // back-reference to the canvas element for which
  // this context was created
  readonly attribute nsIDOMHTMLCanvasElement canvas;

  // state
  [binaryname(MozSave)]
  void save();
  [binaryname(MozRestore)]
  void restore();

  // transformations
  void scale(in float x, in float y);
  void rotate(in float angle);
  void translate(in float x, in float y);
  void transform(in float m11, in float m12, in float m21, in float m22, in float dx, in float dy);
  void setTransform(in float m11, in float m12, in float m21, in float m22, in float dx, in float dy);
  [implicit_jscontext]
  attribute jsval mozCurrentTransform; // [ m11, m12, m21, m22, dx, dy ], i.e. row major
  [implicit_jscontext]
  attribute jsval mozCurrentTransformInverse;

  // compositing
  attribute float globalAlpha; /* default 1.0 -- opaque */
  attribute DOMString globalCompositeOperation; /* default "over" */

  // Colors and Styles

  // These attributes work, but are quickstubbed for JS code.  Native
  // code should use the _multi variants below.
  attribute nsIVariant strokeStyle;
  attribute nsIVariant fillStyle;

  // These do the actual work.  Use these from c++ -- only one of str or iface
  // should be specified; the one that's not null/void is used.  For the getter,
  // ifaceType is 0 if it's a string, 1 if it's a pattern, or 2 if it's a gradient
%{C++
enum CanvasMultiGetterType {
      CMG_STYLE_STRING = 0,
      CMG_STYLE_PATTERN = 1,
      CMG_STYLE_GRADIENT = 2
};
%}
  [noscript] void setStrokeStyle_multi(in DOMString str, in nsISupports iface);
  [noscript] void getStrokeStyle_multi(out DOMString str, out nsISupports iface, out long type);
  [noscript] void setFillStyle_multi(in DOMString str, in nsISupports iface);
  [noscript] void getFillStyle_multi(out DOMString str, out nsISupports iface, out long type);

  //attribute DOMString fillRule;
  attribute DOMString mozFillRule; /* "evenodd", "nonzero" (default) */

  nsIDOMCanvasGradient createLinearGradient (in float x0, in float y0, in float x1, in float y1);
  nsIDOMCanvasGradient createRadialGradient(in float x0, in float y0, in float r0, in float x1, in float y1, in float r1);
  nsIDOMCanvasPattern createPattern(in nsIDOMHTMLElement image, [Null(Stringify)] in DOMString repetition);
  attribute float lineWidth; /* default 1 */
  [binaryname(MozLineCap)]
  attribute DOMString lineCap; /* "butt", "round", "square" (default) */
  [binaryname(MozLineJoin)]
  attribute DOMString lineJoin; /* "round", "bevel", "miter" (default) */
  attribute float miterLimit; /* default 10 */

  [implicit_jscontext]
  attribute jsval mozDash; /* default |null| */
  attribute float mozDashOffset; /* default 0.0 */

  // shadows
  attribute float shadowOffsetX;
  attribute float shadowOffsetY;
  attribute float shadowBlur;
  [binaryname(MozShadowColor)]
  attribute DOMString shadowColor;

  // rects
  void clearRect(in float x, in float y, in float w, in float h);
  void fillRect(in float x, in float y, in float w, in float h);
  void strokeRect(in float x, in float y, in float w, in float h);

  // path API
  [binaryname(MozBeginPath)]
  void beginPath();
  [binaryname(MozClosePath)]
  void closePath();

  void moveTo(in float x, in float y);
  void lineTo(in float x, in float y);
  void quadraticCurveTo(in float cpx, in float cpy, in float x, in float y);
  void bezierCurveTo(in float cp1x, in float cp1y, in float cp2x, in float cp2y, in float x, in float y);
  void arcTo(in float x1, in float y1, in float x2, in float y2, in float radius);
  void arc(in float x, in float y, in float r, in float startAngle, in float endAngle, [optional] in boolean anticlockwise);
  void rect(in float x, in float y, in float w, in float h);

  [binaryname(MozFill)]
  void fill();
  [binaryname(MozStroke)]
  void stroke();
  [binaryname(MozClip)]
  void clip();

  // text api
  [binaryname(MozFont)]
  attribute DOMString font; /* default "10px sans-serif" */
  [binaryname(MozTextAlign)]
  attribute DOMString textAlign; /* "start" (default), "end", "left", "right",
                                 "center" */
  [binaryname(MozTextBaseline)]
  attribute DOMString textBaseline; /* "alphabetic" (default), "top", "hanging",
                                    "middle", "ideographic", "bottom" */

  void fillText(in DOMString text, in float x, in float y, [optional] in float maxWidth);
  void strokeText(in DOMString text, in float x, in float y, [optional] in float maxWidth);
  nsIDOMTextMetrics measureText(in DOMString text);

  [binaryname(TextStyle)]
  attribute DOMString mozTextStyle;

  // image api

  [optional_argc] void drawImage(in nsIDOMElement image,
                                 in float a1, in float a2,
                                 [optional] in float a3,
                                 [optional] in float a4,
                                 [optional] in float a5,
                                 [optional] in float a6,
                                 [optional] in float a7,
                                 [optional] in float a8);

/*
  void drawImage(in HTMLImageElement image, in float dx, in float dy);
  void drawImage(in HTMLImageElement image, in float dx, in float dy, in float sw, in float sh);
  void drawImage(in HTMLImageElement image, in float sx, in float sy, in float sw, in float sh, in float dx, in float dy, in float dw, in float dh);
*/

  // point-membership test
  boolean isPointInPath(in float x, in float y);

  // pixel manipulation
  // ImageData getImageData (in float x, in float y, in float width, in float height);
  // void putImageData (in ImageData d, in float x, in float y);
  // ImageData = { width: #, height: #, data: [r, g, b, a, ...] }

  [implicit_jscontext]
  nsIDOMImageData getImageData(in double sx, in double sy, in double sw, in double sh);

  // This is just a dummy function; for JS, it is implemented as a quickstub
  // that call the _explicit methods below.  Native callers should use the
  // _explicit method directly.
  void putImageData();

  // dataLen must be == width*height*4 in this call
  [noscript] void putImageData_explicit(in long x, in long y, in unsigned long width, in unsigned long height,
                                        [array, size_is(dataLen)] in octet dataPtr, in unsigned long dataLen, in boolean hasDirtyRect,
                                        in long dirtyX, in long dirtyY, in long dirtyWidth, in long dirtyHeight);

  // ImageData createImageData(in float w, in float h);
  // Note: this is basically script-only (and really, quickstub-only).  Native callers
  // should just use the noscript 'explicit' get/put methods above, instead of using
  // a separate ImageData object.
  void createImageData();

  // image smoothing mode -- if disabled, images won't be smoothed
  // if scaled.
  attribute boolean mozImageSmoothingEnabled;

  // Show the caret if appropriate when drawing
  const unsigned long DRAWWINDOW_DRAW_CARET   = 0x01;
  // Don't flush pending layout notifications that could otherwise
  // be batched up
  const unsigned long DRAWWINDOW_DO_NOT_FLUSH = 0x02;
  // Draw scrollbars and scroll the viewport if they are present
  const unsigned long DRAWWINDOW_DRAW_VIEW    = 0x04;
  // Use the widget layer manager if available. This means hardware
  // acceleration may be used, but it might actually be slower or
  // lower quality than normal. It will however more accurately reflect
  // the pixels rendered to the screen.
  const unsigned long DRAWWINDOW_USE_WIDGET_LAYERS = 0x08;
  // Don't synchronously decode images - draw what we have
  const unsigned long DRAWWINDOW_ASYNC_DECODE_IMAGES = 0x10;

  /**
   * Renders a region of a window into the canvas.  The contents of
   * the window's viewport are rendered, ignoring viewport clipping
   * and scrolling.
   *
   * @param x
   * @param y
   * @param w
   * @param h specify the area of the window to render, in CSS
   * pixels.
   *
   * @param backgroundColor the canvas is filled with this color
   * before we render the window into it. This color may be
   * transparent/translucent. It is given as a CSS color string
   * (e.g., rgb() or rgba()).
   *
   * @param flags Used to better control the drawWindow call.
   * Flags can be ORed together.
   *
   * Of course, the rendering obeys the current scale, transform and
   * globalAlpha values.
   *
   * Hints:
   * -- If 'rgba(0,0,0,0)' is used for the background color, the
   * drawing will be transparent wherever the window is transparent.
   * -- Top-level browsed documents are usually not transparent
   * because the user's background-color preference is applied,
   * but IFRAMEs are transparent if the page doesn't set a background.
   * -- If an opaque color is used for the background color, rendering
   * will be faster because we won't have to compute the window's
   * transparency.
   *
   * This API cannot currently be used by Web content. It is chrome
   * only.
   */
  void drawWindow(in nsIDOMWindow window, in float x, in float y,
                  in float w, in float h, in DOMString bgColor,
                  [optional] in unsigned long flags);
  void asyncDrawXULElement(in nsIDOMXULElement elem, in float x, in float y,
                  in float w, in float h, in DOMString bgColor,
                  [optional] in unsigned long flags);
};