canvas.html

J2ME MIDP2.0 final specification

KEY_NUM2</H3>
<PRE>
public static final int <B>KEY_NUM2</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>2</code>.

 <P>Constant value <code>50</code> is set to <code>KEY_NUM2</code>.</P></DL>
<HR>

<A NAME="KEY_NUM3"><!-- --></A><H3>
KEY_NUM3</H3>
<PRE>
public static final int <B>KEY_NUM3</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>3</code>.

 <P>Constant value <code>51</code> is set to <code>KEY_NUM3</code>.</P></DL>
<HR>

<A NAME="KEY_NUM4"><!-- --></A><H3>
KEY_NUM4</H3>
<PRE>
public static final int <B>KEY_NUM4</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>4</code>.

 <P>Constant value <code>52</code> is set to <code>KEY_NUM4</code>.</P></DL>
<HR>

<A NAME="KEY_NUM5"><!-- --></A><H3>
KEY_NUM5</H3>
<PRE>
public static final int <B>KEY_NUM5</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>5</code>.

 <P>Constant value <code>53</code> is set to <code>KEY_NUM5</code>.</P></DL>
<HR>

<A NAME="KEY_NUM6"><!-- --></A><H3>
KEY_NUM6</H3>
<PRE>
public static final int <B>KEY_NUM6</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>6</code>.

 <P>Constant value <code>54</code> is set to <code>KEY_NUM6</code>.</P></DL>
<HR>

<A NAME="KEY_NUM7"><!-- --></A><H3>
KEY_NUM7</H3>
<PRE>
public static final int <B>KEY_NUM7</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>7</code>.

 <P>Constant value <code>55</code> is set to <code>KEY_NUM7</code>.</P></DL>
<HR>

<A NAME="KEY_NUM8"><!-- --></A><H3>
KEY_NUM8</H3>
<PRE>
public static final int <B>KEY_NUM8</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>8</code>.

 <P>Constant value <code>56</code> is set to <code>KEY_NUM8</code>.</P></DL>
<HR>

<A NAME="KEY_NUM9"><!-- --></A><H3>
KEY_NUM9</H3>
<PRE>
public static final int <B>KEY_NUM9</B></PRE>
<DL>
<DD>keyCode for ITU-T key <code>9</code>.

 <P>Constant value <code>57</code> is set to <code>KEY_NUM09</code>.</P></DL>
<HR>

<A NAME="KEY_STAR"><!-- --></A><H3>
KEY_STAR</H3>
<PRE>
public static final int <B>KEY_STAR</B></PRE>
<DL>
<DD>keyCode for ITU-T key &quot;star&quot; (<code>*</code>).

 <P>Constant value <code>42</code> is set to <code>KEY_STAR</code>.</P></DL>
<HR>

<A NAME="KEY_POUND"><!-- --></A><H3>
KEY_POUND</H3>
<PRE>
public static final int <B>KEY_POUND</B></PRE>
<DL>
<DD>keyCode for ITU-T key &quot;pound&quot; (<code>#</code>).

 <P>Constant value <code>35</code> is set to <code>KEY_POUND</code>.</P></DL>

<!-- ========= CONSTRUCTOR DETAIL ======== -->

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<TD COLSPAN=1><FONT SIZE="+2">
<B>Constructor Detail</B></FONT></TD>
</TR>
</TABLE>

<A NAME="Canvas()"><!-- --></A><H3>
Canvas</H3>
<PRE>
protected <B>Canvas</B>()</PRE>
<DL>
<DD>Constructs a new <code>Canvas</code> object.</DL>

<!-- ============ METHOD DETAIL ========== -->

<A NAME="method_detail"><!-- --></A>
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<B>Method Detail</B></FONT></TD>
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</TABLE>

<A NAME="getWidth()"><!-- --></A><H3>
getWidth</H3>
<PRE>
public int <B>getWidth</B>()</PRE>
<DL>
<DD>Gets the width in pixels of the displayable area of the
 <code>Canvas</code>.  The
 value returned may change during execution.  If it does, the 
 application will be notified through a call to the
 <A HREF="../../../javax/microedition/lcdui/Canvas.html#sizeChanged(int, int)"><CODE>sizeChanged(int, int)</CODE></A> method.<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../javax/microedition/lcdui/Displayable.html#getWidth()">getWidth</A></CODE> in class <CODE><A HREF="../../../javax/microedition/lcdui/Displayable.html">Displayable</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>width of the displayable area</DL>
</DD>
</DL>
<HR>

<A NAME="getHeight()"><!-- --></A><H3>
getHeight</H3>
<PRE>
public int <B>getHeight</B>()</PRE>
<DL>
<DD>Gets the height in pixels of the displayable area of the
 <code>Canvas</code>.  The
 value returned may change during execution.  If it does, the 
 application will be notified through a call to the
 <A HREF="../../../javax/microedition/lcdui/Canvas.html#sizeChanged(int, int)"><CODE>sizeChanged(int, int)</CODE></A> method.<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../../javax/microedition/lcdui/Displayable.html#getHeight()">getHeight</A></CODE> in class <CODE><A HREF="../../../javax/microedition/lcdui/Displayable.html">Displayable</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>height of the displayable area</DL>
</DD>
</DL>
<HR>

<A NAME="isDoubleBuffered()"><!-- --></A><H3>
isDoubleBuffered</H3>
<PRE>
public boolean <B>isDoubleBuffered</B>()</PRE>
<DL>
<DD>Checks if the <code>Canvas</code> is double buffered by the
 implementation.<DD><DL>
<DT><B>Returns:</B><DD><code>true</code> if double buffered,
 <code>false</code> otherwise</DL>
</DD>
</DL>
<HR>

<A NAME="hasPointerEvents()"><!-- --></A><H3>
hasPointerEvents</H3>
<PRE>
public boolean <B>hasPointerEvents</B>()</PRE>
<DL>
<DD>Checks if the platform supports pointer press and release events.<DD><DL>
<DT><B>Returns:</B><DD><code>true</code> if the device supports pointer events</DL>
</DD>
</DL>
<HR>

<A NAME="hasPointerMotionEvents()"><!-- --></A><H3>
hasPointerMotionEvents</H3>
<PRE>
public boolean <B>hasPointerMotionEvents</B>()</PRE>
<DL>
<DD>Checks if the platform supports pointer motion events (pointer dragged).
 Applications may use this method to determine if the platform is capable
 of supporting motion events.<DD><DL>
<DT><B>Returns:</B><DD><code>true</code> if the device supports pointer motion events</DL>
</DD>
</DL>
<HR>

<A NAME="hasRepeatEvents()"><!-- --></A><H3>
hasRepeatEvents</H3>
<PRE>
public boolean <B>hasRepeatEvents</B>()</PRE>
<DL>
<DD>Checks if the platform can generate repeat events when key
 is kept down.<DD><DL>
<DT><B>Returns:</B><DD><code>true</code> if the device supports repeat events</DL>
</DD>
</DL>
<HR>

<A NAME="getKeyCode(int)"><!-- --></A><H3>
getKeyCode</H3>
<PRE>
public int <B>getKeyCode</B>(int&nbsp;gameAction)</PRE>
<DL>
<DD>Gets a key code that corresponds to the specified game action on the
 device.  The implementation is required to provide a mapping for every
 game action, so this method will always return a valid key code for
 every game action.  See <a href="#gameactions">above</a> for further
 discussion of game actions.  There may be multiple keys associated
 with the same game action; however, this method will return only one of
 them.  Applications should translate the key code of every key event
 into a game action using <A HREF="../../../javax/microedition/lcdui/Canvas.html#getGameAction(int)"><CODE>getGameAction(int)</CODE></A> and then interpret the 
 resulting game action, instead of generating a table of key codes at 
 using this method during initialization.
 
 <P>The mapping between key codes and game actions
 will not change during the execution of the application.</P><DD><DL>
<DT><B>Parameters:</B><DD><CODE>gameAction</CODE> - the game action<DT><B>Returns:</B><DD>a key code corresponding to this game action<DT><B>Throws:</B><DD><CODE>IllegalArgumentException</CODE> - if <code>gameAction</code> 
 is not a valid game action</DL>
</DD>
</DL>
<HR>

<A NAME="getKeyName(int)"><!-- --></A><H3>
getKeyName</H3>
<PRE>
public String <B>getKeyName</B>(int&nbsp;keyCode)</PRE>
<DL>
<DD>Gets an informative key string for a key. The string returned will
 resemble the text physically printed on the key.  This string is 
 suitable for displaying to the user.  For example, on a device
 with function keys <code>F1</code> through <code>F4</code>,
 calling this method on the <code>keyCode</code> for
 the <code>F1</code> key will return the string
 &quot;<code>F1</code>&quot;. A typical use for this string
 will be to compose help text such as &quot;Press
 <code>F1</code> to proceed.&quot;

 <p> This method will return a non-empty string for every valid key code.
 </p>

 <p> There is no direct mapping from game actions to key names. To get
 the string name for a game action <code>GAME_A</code>, the
 application must call </p>

 <TABLE BORDER="2">
 <TR>
 <TD ROWSPAN="1" COLSPAN="1">
    <pre><code>
    getKeyName(getKeyCode(GAME_A));    </code></pre>
 </TD>
 </TR>
 </TABLE><DD><DL>
<DT><B>Parameters:</B><DD><CODE>keyCode</CODE> - the key code being requested<DT><B>Returns:</B><DD>a string name for the key<DT><B>Throws:</B><DD><CODE>IllegalArgumentException</CODE> - if <code>keyCode</code> 
 is not a valid key code</DL>
</DD>
</DL>
<HR>

<A NAME="getGameAction(int)"><!-- --></A><H3>
getGameAction</H3>
<PRE>
public int <B>getGameAction</B>(int&nbsp;keyCode)</PRE>
<DL>
<DD>Gets the game action associated with the given key code of the
 device.  Returns zero if no game action is associated with this key
 code.  See <a href="#gameactions">above</a> for further discussion of
 game actions. 

 <P>The mapping between key codes and game actions
 will not change during the execution of the application.</P><DD><DL>
<DT><B>Parameters:</B><DD><CODE>keyCode</CODE> - the key code<DT><B>Returns:</B><DD>the game action corresponding to this key, or 
 <code>0</code> if none<DT><B>Throws:</B><DD><CODE>IllegalArgumentException</CODE> - if <code>keyCode</code> 
 is not a valid key code</DL>
</DD>
</DL>
<HR>

<A NAME="setFullScreenMode(boolean)"><!-- --></A><H3>
setFullScreenMode</H3>
<PRE>
public void <B>setFullScreenMode</B>(boolean&nbsp;mode)</PRE>
<DL>
<DD>Controls whether the <code>Canvas</code> is in full-screen mode
 or in normal mode.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>mode</CODE> - <code>true</code> if the <code>Canvas</code>
 is to be in full screen mode, <code>false</code> otherwise<DT><B>Since: </B><DD>MIDP 2.0</DD>
</DL>
</DD>
</DL>
<HR>

<A NAME="keyPressed(int)"><!-- --></A><H3>
keyPressed</H3>
<PRE>
protected void <B>keyPressed</B>(int&nbsp;keyCode)</PRE>
<DL>
<DD>Called when a key is pressed.