GralCanvasStorage

java.lang.Object
- org.vishia.gral.base.GralCanvasStorage

All Implemented Interfaces:

GralCanvas_ifc
```
public class GralCanvasStorage
extends java.lang.Object
implements GralCanvas_ifc
```
The canvas storage is a storage, which stores figures to draw. This figures are drawn if the redraw-routine from the window-system is invoked.

A canvas is organized containing some GralCanvasStorage.Figure. A figure has a position (GralPos) and only one or some GralCanvasStorage.FigureData. For more as one FigureData per Figure the container GralCanvasStorage.FigureDataSet is used.

GralCanvasStorage.FigureData and GralCanvasStorage.FigureDataSet can be created independent of a GralCanvasStorage.Figure and used in more as one figure on different positions, with similar presentation:
```
  /**Dataset of the border of the data words in memory:
  +--+--+
 |  |  |
 +--+--+ 
 It is used for all Mem presentation (Master and Slave).
 /
  final GralCanvasStorage.FigureDataSet figData_Words = new GralCanvasStorage.FigureDataSet(); {
    GralColor color = GralColor.getColor("bk");
    this.figData_Words.addPolyline(color).point(0, 0).point(0,2);  // |
    for(int ix = 0; ix <20; ++ix) {
      this.figData_Words.addPolyline(color)
      .point(ix,2)
      .point(ix+1,2)  // --+    20 times gives rectangles for each word.
      .point(ix+1,0)  //   |
      .point(ix,0);   // --+
    }
  }
  
```
Above it is an example to define the appearance of a figure as FigureDataSet on construction inside a class. To use it in two figures, the application should call in an initialization phase before establishing the graphic:
```
  void init() throws ParseException {
    //
    this.pos.setPosition("10-2,10+1++");
    this.canvas.addFigure("dataWordsMaster", this.pos, this.figData_Words, false);

    this.pos.setPosition("10-2,40+1++");
    this.canvas.addFigure("dataWordsSlave1", this.pos, this.figData_Words, false);
   
```
Dynamic figures
You can mark a figure as dynamic (last argument of addFigure(String, GralPos, FigureDataSet, boolean) above). If you invoke GralWidget.redrawOnlyDynamics(int, int) or GralWidget.redraw(int, int, boolean) with true as last argument then only these figures are drawn, the background of the canvas will not be deleted. This prevents flickering effects on the screen because the delay after clean and redraw all. The coordinates of the area of a figure are calculated. Before drawing the figure the canvas content is stored in the heap, using a proper container such as org.eclipse.swt.graphics.Image. Before redraw the figure this canvas content is restored. This process should be well organized, meaningful if more as one figures overlap. But this is done in the implementation level of the library SwtWdgCanvas for the SWT implementation.
You can change properties of the figures before the redraw(...) invocation, especially the position and the color. Then this new appearance is showing.
Of course the given presentation of the figure should be firstly removed on the old position by restoration of the background before the last drawing was done. For dynamic figures the background before drawing is stored to restore later. The spread of this background is a parameterized property of the figure. This parameterization should be well done, comprehensive for the figure, but not too much. It is important that such areas does not overlap too much, then the order of restoration will become important, and that is not so simple to do.
A figure can be set to visible or not: GralCanvasStorage.Figure.show(boolean). Now a special case is possible: If a figure is shown for only one step, its restoration of the background is done firstly. Then an overlap problem is solved.
If the screen should be drawn newly because the window was minimized before, then of couse all is redrawn.

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static class`	`GralCanvasStorage.Arcus`
`static class`	`GralCanvasStorage.Figure` Data class to store some representation data of a figure.
`static class`	`GralCanvasStorage.FigureData` This is the common abstract class for all data which describes one part of a figure.
`static class`	`GralCanvasStorage.FigureDataSet`
`static class`	`GralCanvasStorage.FigureText`
`static class`	`GralCanvasStorage.Fillin`
`static class`	`GralCanvasStorage.KindFigureData`
`static class`	`GralCanvasStorage.PaintOrderImage`
`static class`	`GralCanvasStorage.PolyLine`
`static class`	`GralCanvasStorage.PolyLineFloatArray`
`static class`	`GralCanvasStorage.SimpleLine`

Field Summary

Fields
Modifier and Type	Field and Description
`java.util.Map<java.lang.String,GralCanvasStorage.Figure>`	`idxFigure` Only used to prevent and check name clashes between figures.
`java.util.concurrent.ConcurrentLinkedQueue<GralCanvasStorage.Figure>`	`paintOrders` List of all orders to paint in `#drawBackground(GC, int, int, int, int)`.
`static java.lang.String`	`version` Version, history and license.
`(package private) java.util.List<GralCanvasStorage.Figure>`	`XXXdynamicOrder` If dynamic figures are available, this list contains the draw order.

Constructor Summary

Constructors
Constructor and Description

GralCanvasStorage()

Constructors
Constructor and Description
`GralCanvasStorage()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`GralCanvasStorage.Figure`	`addFigure(java.lang.String name, GralPos pos, boolean isDynamic)` Adds a simple figure with only one FigureData for example one line.
`GralCanvasStorage.Figure`	`addFigure(java.lang.String name, GralPos pos, GralCanvasStorage.FigureData data, boolean isDynamic)` Adds a simple figure with only one FigureData for example one line.
`GralCanvasStorage.Figure`	`addFigure(java.lang.String name, GralPos pos, GralCanvasStorage.FigureDataSet data, boolean isDynamic)` Adds a complex figure with a FigureDataSet
`void`	`drawFillin(GralPos pos, GralColor color)`
`void`	`drawImage(GralImageBase image, int x, int y, int dx, int dy, GralRectangle imagePixelSize)`
`void`	`drawLine(GralColor color, GralCanvasArea.UserUnits userUnits, float[][] points, int iy)` Accepts a order to draw a line.
`void`	`drawLine(GralColor color, int x1, int y1, int x2, int y2)` Accepts a order to draw a line.
`void`	`drawLine(GralPos pos, GralColor color, java.util.List<GralPoint> points)` Accepts a order to draw a line.
`void`	`drawText(java.lang.String text)`
`void`	`setTextStyle(GralColor color, GralFont font, int origin)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - version
```
public static final java.lang.String version
```
    Version, history and license.
    - 2022-11-06 Hartmut new concept, one GralCanvasStorage.Figure can contain more as one GralCanvasStorage.FigureData, which allows one Object with several lines or areas with a common position.
    - 2012-09-27 Hartmut new: GralCanvasStorage.PolyLineFloatArray
    - 2012-04-22 new drawLine(GralPos, GralColor, List), improved GralCanvasStorage.Figure-derivates.
    - 2011-06-00 Hartmut created
    Copyright/Copyleft:
    For this source the LGPL Lesser General Public License, published by the Free Software Foundation is valid. It means:
    1. You can use this source without any restriction for any desired purpose.
    2. You can redistribute copies of this source to everybody.
    3. Every user of this source, also the user of redistribute copies with or without payment, must accept this license for further using.
    4. But the LPGL is not appropriate for a whole software product, if this source is only a part of them. It means, the user must publish this part of source, but doesn't need to publish the whole source of the own product.
    5. You can study and modify (improve) this source for own using or for redistribution, but you have to license the modified sources likewise under this LGPL Lesser General Public License. You mustn't delete this Copyright/Copyleft inscription in this source file.
    If you intent to use this source without publishing its usage, you can get a second license subscribing a special contract with the author.
    See Also:
    
    Constant Field Values
  - paintOrders
```
public final java.util.concurrent.ConcurrentLinkedQueue<GralCanvasStorage.Figure> paintOrders
```
    List of all orders to paint in #drawBackground(GC, int, int, int, int).
  - idxFigure
```
public final java.util.Map<java.lang.String,GralCanvasStorage.Figure> idxFigure
```
    Only used to prevent and check name clashes between figures.
  - XXXdynamicOrder
```
java.util.List<GralCanvasStorage.Figure> XXXdynamicOrder
```
    If dynamic figures are available, this list contains the draw order. On restoring the static context the reverse order is used.
- Constructor Detail
  - GralCanvasStorage
```
public GralCanvasStorage()
```
- Method Detail
  - addFigure
```
public GralCanvasStorage.Figure addFigure(java.lang.String name,
                                          GralPos pos,
                                          boolean isDynamic)
```
    Adds a simple figure with only one FigureData for example one line.
    
    Parameters:
    
    pos -
    
    color -
    
    data -
    
    isDynamic -
  - addFigure
```
public GralCanvasStorage.Figure addFigure(java.lang.String name,
                                          GralPos pos,
                                          GralCanvasStorage.FigureData data,
                                          boolean isDynamic)
```
    Adds a simple figure with only one FigureData for example one line.
    
    Parameters:
    
    pos -
    
    color -
    
    data -
    
    isDynamic -
  - addFigure
```
public GralCanvasStorage.Figure addFigure(java.lang.String name,
                                          GralPos pos,
                                          GralCanvasStorage.FigureDataSet data,
                                          boolean isDynamic)
```
    Adds a complex figure with a FigureDataSet
    
    Parameters:
    
    pos -
    
    color -
    
    data -
    
    isDynamic -
    
    Returns:
  - drawLine
```
public void drawLine(GralColor color,
                     int x1,
                     int y1,
                     int x2,
                     int y2)
```
    Accepts a order to draw a line. The coordinates are stored only. This method can be called in any thread. It is thread-safe.
    
    Specified by:
    
    drawLine in interface GralCanvas_ifc
    
    Parameters:
    
    color -
    
    x1 - TODO yet it is pixel coordinates, use GralGrid coordinates.
    
    y1 -
    
    x2 -
    
    y2 -
  - drawLine
```
public void drawLine(GralPos pos,
                     GralColor color,
                     java.util.List<GralPoint> points)
```
    Accepts a order to draw a line. The coordinates are stored only. This method can be called in any thread. It is thread-safe.
    
    Parameters:
    
    color -
  - drawLine
```
public void drawLine(GralColor color,
                     GralCanvasArea.UserUnits userUnits,
                     float[][] points,
                     int iy)
```
    Accepts a order to draw a line. The coordinates are stored only. This method can be called in any thread. It is thread-safe.
    
    Parameters:
    
    color -
  - drawFillin
```
public void drawFillin(GralPos pos,
                       GralColor color)
```
  - drawImage
```
public void drawImage(GralImageBase image,
                      int x,
                      int y,
                      int dx,
                      int dy,
                      GralRectangle imagePixelSize)
```
    Specified by:
    
    drawImage in interface GralCanvas_ifc
  - drawText
```
public void drawText(java.lang.String text)
```
    Specified by:
    
    drawText in interface GralCanvas_ifc
  - setTextStyle
```
public void setTextStyle(GralColor color,
                         GralFont font,
                         int origin)
```
    Specified by:
    
    setTextStyle in interface GralCanvas_ifc

Class GralCanvasStorage

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

version

paintOrders

idxFigure

XXXdynamicOrder

Constructor Detail

GralCanvasStorage

Method Detail

addFigure

addFigure

addFigure

drawLine

drawLine

drawLine

drawFillin

drawImage

drawText

setTextStyle