JFreeChart:更新图表时保留缩放位置
我的程序使用 JFreeChart(通过 Swing ChartPanel)创建时间序列图表,并允许用户放大它(使用 ChartPanel 的标准缩放功能)。该程序具有可以在运行时调整的参数(例如平滑);如果进行调整,图表将使用 ChartPanel 的“setChart()”方法进行替换。然而,所有调整的时间范围始终保持不变。
当调用“setChart()”时,缩放位置会重置,以便显示整个图表。我现在想要的是在调用“setChart()”后保留缩放位置,以便用户可以直接在任何所需的缩放级别观察调整效果。这怎么可能?
My program creates a time series chart using JFreeChart (via Swing ChartPanel) and allows the user to zoom into it (using the ChartPanel's standard zoom feature). The program has parameters (such as smoothing) that can be tweaked at runtime; if tweaked, the chart is replaced using the ChartPanel's "setChart()" method. The timeframe, however, invariably stays the same across all tweaks.
When "setChart()" is called, the zoom position is reset so that the entire chart is shown. What I now want is for the zoom position to be preserved after the call to "setChart()", so that the user can observe tweak effects directly at any desired zoom level. How is that possible?
ChartPanel
具有方法getScaleX()
和getScaleY()
,可用于缓存当前缩放状态,以便以后通过其中一种缩放方法进行恢复。有一个相关示例 在这里。ChartPanel
has methodsgetScaleX()
andgetScaleY()
that could be used to cache the current zoom state for later restoration by one of the zoom methods. There's a related example here.