/*
Copyright (c) 2012 Emitrom LLC. All rights reserved.
For licensing questions, please contact us at licensing@emitrom.com
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package com.emitrom.lienzo.client.core.util;
import com.emitrom.lienzo.client.core.Context2D;
import com.emitrom.lienzo.client.core.LienzoGlobals;
import com.emitrom.lienzo.client.core.NativeContext2D;
import com.emitrom.lienzo.shared.core.types.DataURLType;
import com.google.gwt.dom.client.CanvasElement;
import com.google.gwt.dom.client.Document;
public final class ScratchCanvas
{
private final int m_wide;
private final int m_high;
private final CanvasElement m_element;
private final Context2D m_context;
public ScratchCanvas(int wide, int high)
{
m_wide = wide;
m_high = high;
if (LienzoGlobals.getInstance().isCanvasSupported())
{
m_element = Document.get().createCanvasElement();
m_element.setWidth(wide);
m_element.setHeight(high);
m_context = new Context2D(getNativeContext2D(m_element));
}
else
{
m_element = null;
m_context = null;
}
}
public final void clear()
{
Context2D context = getContext();
if (null != context)
{
context.clearRect(0, 0, m_wide, m_high);
}
}
public final int getWidth()
{
return m_wide;
}
public final int getHeight()
{
return m_high;
}
public final Context2D getContext()
{
return m_context;
}
public final String toDataURL()
{
if (null != m_element)
{
return toDataURL(m_element);
}
else
{
return "data:,";
}
}
public final String toDataURL(DataURLType mimetype)
{
if (null != m_element)
{
if (null == mimetype)
{
mimetype = DataURLType.PNG;
}
return toDataURL(m_element, mimetype.getValue());
}
else
{
return "data:,";
}
}
private static native final String toDataURL(CanvasElement element)
/*-{
return element.toDataURL();
}-*/;
// TODO other arguments, e.g. for image/jpeg The second argument, if it is a number in the range 0.0 to 1.0 inclusive, must be treated as the desired quality level. If it is not a number or is outside that range, the user agent must use its default value, as if the argument had been omitted.
private static native final String toDataURL(CanvasElement element, String mimetype)
/*-{
return element.toDataURL(mimetype);
}-*/;
private static final native NativeContext2D getNativeContext2D(CanvasElement element)
/*-{
return element.getContext("2d");
}-*/;
}