chartutilities.html

jfreechart1。0。2的api。

<FONT color="green">134</FONT>         * @throws IOException if there are any I/O errors.<a name="line.134"></a>
<FONT color="green">135</FONT>         */<a name="line.135"></a>
<FONT color="green">136</FONT>        public static void writeChartAsPNG(OutputStream out,<a name="line.136"></a>
<FONT color="green">137</FONT>                                           JFreeChart chart,<a name="line.137"></a>
<FONT color="green">138</FONT>                                           int width,<a name="line.138"></a>
<FONT color="green">139</FONT>                                           int height,<a name="line.139"></a>
<FONT color="green">140</FONT>                                           boolean encodeAlpha,<a name="line.140"></a>
<FONT color="green">141</FONT>                                           int compression) throws IOException {<a name="line.141"></a>
<FONT color="green">142</FONT>    <a name="line.142"></a>
<FONT color="green">143</FONT>            // defer argument checking...<a name="line.143"></a>
<FONT color="green">144</FONT>            ChartUtilities.writeChartAsPNG(<a name="line.144"></a>
<FONT color="green">145</FONT>                out, chart, width, height, null, encodeAlpha, compression<a name="line.145"></a>
<FONT color="green">146</FONT>            );<a name="line.146"></a>
<FONT color="green">147</FONT>    <a name="line.147"></a>
<FONT color="green">148</FONT>        }<a name="line.148"></a>
<FONT color="green">149</FONT>    <a name="line.149"></a>
<FONT color="green">150</FONT>        /**<a name="line.150"></a>
<FONT color="green">151</FONT>         * Writes a chart to an output stream in PNG format.  This method allows <a name="line.151"></a>
<FONT color="green">152</FONT>         * you to pass in a {@link ChartRenderingInfo} object, to collect <a name="line.152"></a>
<FONT color="green">153</FONT>         * information about the chart dimensions/entities.  You will need this <a name="line.153"></a>
<FONT color="green">154</FONT>         * info if you want to create an HTML image map.<a name="line.154"></a>
<FONT color="green">155</FONT>         *<a name="line.155"></a>
<FONT color="green">156</FONT>         * @param out  the output stream (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.156"></a>
<FONT color="green">157</FONT>         * @param chart  the chart (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.157"></a>
<FONT color="green">158</FONT>         * @param width  the image width.<a name="line.158"></a>
<FONT color="green">159</FONT>         * @param height  the image height.<a name="line.159"></a>
<FONT color="green">160</FONT>         * @param info  the chart rendering info (&lt;code&gt;null&lt;/code&gt; permitted).<a name="line.160"></a>
<FONT color="green">161</FONT>         *<a name="line.161"></a>
<FONT color="green">162</FONT>         * @throws IOException if there are any I/O errors.<a name="line.162"></a>
<FONT color="green">163</FONT>         */<a name="line.163"></a>
<FONT color="green">164</FONT>        public static void writeChartAsPNG(OutputStream out,<a name="line.164"></a>
<FONT color="green">165</FONT>                                           JFreeChart chart,<a name="line.165"></a>
<FONT color="green">166</FONT>                                           int width,<a name="line.166"></a>
<FONT color="green">167</FONT>                                           int height,<a name="line.167"></a>
<FONT color="green">168</FONT>                                           ChartRenderingInfo info) <a name="line.168"></a>
<FONT color="green">169</FONT>            throws IOException {<a name="line.169"></a>
<FONT color="green">170</FONT>    <a name="line.170"></a>
<FONT color="green">171</FONT>            if (chart == null) {<a name="line.171"></a>
<FONT color="green">172</FONT>                throw new IllegalArgumentException("Null 'chart' argument.");<a name="line.172"></a>
<FONT color="green">173</FONT>            }<a name="line.173"></a>
<FONT color="green">174</FONT>            BufferedImage bufferedImage <a name="line.174"></a>
<FONT color="green">175</FONT>                = chart.createBufferedImage(width, height, info);<a name="line.175"></a>
<FONT color="green">176</FONT>            EncoderUtil.writeBufferedImage(bufferedImage, ImageFormat.PNG, out);<a name="line.176"></a>
<FONT color="green">177</FONT>        }<a name="line.177"></a>
<FONT color="green">178</FONT>    <a name="line.178"></a>
<FONT color="green">179</FONT>        /**<a name="line.179"></a>
<FONT color="green">180</FONT>         * Writes a chart to an output stream in PNG format.  This method allows <a name="line.180"></a>
<FONT color="green">181</FONT>         * you to pass in a {@link ChartRenderingInfo} object, to collect <a name="line.181"></a>
<FONT color="green">182</FONT>         * information about the chart dimensions/entities.  You will need this <a name="line.182"></a>
<FONT color="green">183</FONT>         * info if you want to create an HTML image map.<a name="line.183"></a>
<FONT color="green">184</FONT>         *<a name="line.184"></a>
<FONT color="green">185</FONT>         * @param out  the output stream (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.185"></a>
<FONT color="green">186</FONT>         * @param chart  the chart (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.186"></a>
<FONT color="green">187</FONT>         * @param width  the image width.<a name="line.187"></a>
<FONT color="green">188</FONT>         * @param height  the image height.<a name="line.188"></a>
<FONT color="green">189</FONT>         * @param info  carries back chart rendering info (&lt;code&gt;null&lt;/code&gt; <a name="line.189"></a>
<FONT color="green">190</FONT>         *              permitted).<a name="line.190"></a>
<FONT color="green">191</FONT>         * @param encodeAlpha  encode alpha?<a name="line.191"></a>
<FONT color="green">192</FONT>         * @param compression  the PNG compression level (0-9).<a name="line.192"></a>
<FONT color="green">193</FONT>         *<a name="line.193"></a>
<FONT color="green">194</FONT>         * @throws IOException if there are any I/O errors.<a name="line.194"></a>
<FONT color="green">195</FONT>         */<a name="line.195"></a>
<FONT color="green">196</FONT>        public static void writeChartAsPNG(OutputStream out,<a name="line.196"></a>
<FONT color="green">197</FONT>                                           JFreeChart chart,<a name="line.197"></a>
<FONT color="green">198</FONT>                                           int width, int height,<a name="line.198"></a>
<FONT color="green">199</FONT>                                           ChartRenderingInfo info,<a name="line.199"></a>
<FONT color="green">200</FONT>                                           boolean encodeAlpha,<a name="line.200"></a>
<FONT color="green">201</FONT>                                           int compression) throws IOException {<a name="line.201"></a>
<FONT color="green">202</FONT>    <a name="line.202"></a>
<FONT color="green">203</FONT>            if (out == null) {<a name="line.203"></a>
<FONT color="green">204</FONT>                throw new IllegalArgumentException("Null 'out' argument.");<a name="line.204"></a>
<FONT color="green">205</FONT>            }<a name="line.205"></a>
<FONT color="green">206</FONT>            if (chart == null) {<a name="line.206"></a>
<FONT color="green">207</FONT>                throw new IllegalArgumentException("Null 'chart' argument.");<a name="line.207"></a>
<FONT color="green">208</FONT>            }<a name="line.208"></a>
<FONT color="green">209</FONT>            BufferedImage chartImage = chart.createBufferedImage(<a name="line.209"></a>
<FONT color="green">210</FONT>                width, height, BufferedImage.TYPE_INT_ARGB, info<a name="line.210"></a>
<FONT color="green">211</FONT>            );<a name="line.211"></a>
<FONT color="green">212</FONT>            ChartUtilities.writeBufferedImageAsPNG(<a name="line.212"></a>
<FONT color="green">213</FONT>                out, chartImage, encodeAlpha, compression<a name="line.213"></a>
<FONT color="green">214</FONT>            );<a name="line.214"></a>
<FONT color="green">215</FONT>    <a name="line.215"></a>
<FONT color="green">216</FONT>        }<a name="line.216"></a>
<FONT color="green">217</FONT>    <a name="line.217"></a>
<FONT color="green">218</FONT>        /**<a name="line.218"></a>
<FONT color="green">219</FONT>         * Writes a scaled version of a chart to an output stream in PNG format.<a name="line.219"></a>
<FONT color="green">220</FONT>         *<a name="line.220"></a>
<FONT color="green">221</FONT>         * @param out  the output stream (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.221"></a>
<FONT color="green">222</FONT>         * @param chart  the chart (&lt;code&gt;null&lt;/code&gt; not permitted).<a name="line.222"></a>
<FONT color="green">223</FONT>         * @param width  the unscaled chart width.<a name="line.223"></a>
<FONT color="green">224</FONT>         * @param height  the unscaled chart height.<a name="line.224"></a>
<FONT color="green">225</FONT>         * @param widthScaleFactor  the horizontal scale factor.<a name="line.225"></a>
<FONT color="green">226</FONT>         * @param heightScaleFactor  the vertical scale factor.<a name="line.226"></a>
<FONT color="green">227</FONT>         *<a name="line.227"></a>
<FONT color="green">228</FONT>         * @throws IOException if there are any I/O problems.<a name="line.228"></a>
<FONT color="green">229</FONT>         */<a name="line.229"></a>
<FONT color="green">230</FONT>        public static void writeScaledChartAsPNG(OutputStream out,<a name="line.230"></a>
<FONT color="green">231</FONT>                                                 JFreeChart chart,<a name="line.231"></a>
<FONT color="green">232</FONT>                                                 int width,<a name="line.232"></a>
<FONT color="green">233</FONT>                                                 int height,<a name="line.233"></a>
<FONT color="green">234</FONT>                                                 int widthScaleFactor,<a name="line.234"></a>
<FONT color="green">235</FONT>                                                 int heightScaleFactor) <a name="line.235"></a>
<FONT color="green">236</FONT>            throws IOException {<a name="line.236"></a>
<FONT color="green">237</FONT>    <a name="line.237"></a>
<FONT color="green">238</FONT>            if (out == null) {<a name="line.238"></a>
<FONT color="green">239</FONT>                throw new IllegalArgumentException("Null 'out' argument.");<a name="line.239"></a>
<FONT color="green">240</FONT>            }<a name="line.240"></a>
<FONT color="green">241</FONT>            if (chart == null) {<a name="line.241"></a>
<FONT color="green">242</FONT>                throw new IllegalArgumentException("Null 'chart' argument.");<a name="line.242"></a>
<FONT color="green">243</FONT>            }<a name="line.243"></a>
<FONT color="green">244</FONT>    <a name="line.244"></a>
<FONT color="green">245</FONT>            double desiredWidth = width * widthScaleFactor;<a name="line.245"></a>
<FONT color="green">246</FONT>            double desiredHeight = height * heightScaleFactor;<a name="line.246"></a>
<FONT color="green">247</FONT>            double defaultWidth = width;<a name="line.247"></a>
<FONT color="green">248</FONT>            double defaultHeight = height;<a name="line.248"></a>
<FONT color="green">249</FONT>            boolean scale = false;<a name="line.249"></a>
<FONT color="green">250</FONT>    <a name="line.250"></a>
<FONT color="green">251</FONT>            // get desired width and height from somewhere then...<a name="line.251"></a>
<FONT color="green">252</FONT>            if ((widthScaleFactor != 1) || (heightScaleFactor != 1)) {<a name="line.252"></a>
<FONT color="green">253</FONT>                scale = true;<a name="line.253"></a>
<FONT color="green">254</FONT>            }<a name="line.254"></a>
<FONT color="green">255</FONT>    <a name="line.255"></a>
<FONT color="green">256</FONT>            double scaleX = desiredWidth / defaultWidth;<a name="line.256"></a>
<FONT color="green">257</FONT>            double scaleY = desiredHeight / defaultHeight;<a name="line.257"></a>
<FONT color="green">258</FONT>    <a name="line.258"></a>
<FONT color="green">259</FONT>            BufferedImage image = new BufferedImage(<a name="line.259"></a>
<FONT color="green">260</FONT>                (int) desiredWidth, (int) desiredHeight, BufferedImage.TYPE_INT_ARGB<a name="line.260"></a>
<FONT color="green">261</FONT>            );<a name="line.261"></a>
<FONT color="green">262</FONT>            Graphics2D g2 = image.createGraphics();<a name="line.262"></a>
<FONT color="green">263</FONT>    <a name="line.263"></a>
<FONT color="green">264</FONT>            if (scale) {<a name="line.264"></a>
<FONT color="green">265</FONT>                AffineTransform saved = g2.getTransform();<a name="line.265"></a>
<FONT color="green">266</FONT>                g2.transform(AffineTransform.getScaleInstance(scaleX, scaleY));<a name="line.266"></a>
<FONT color="green">267</FONT>                chart.draw(<a name="line.267"></a>
<FONT color="green">268</FONT>                    g2, new Rectangle2D.Double(0, 0, defaultWidth, defaultHeight), <a name="line.268"></a>
<FONT color="green">269</FONT>                    null, null<a name="line.269"></a>