ENVI 扩展：从 ENVI ROI 获取通知
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ENVI 扩展：从 ENVI ROI 获取通知
匿名 2016年2月25日 星期四
我最近的一个项目需要一个 ENVI 扩展来响应在 ENVI 图层管理器中进行的 ROI 更改。幸运的是，ENVI 提供了一种机制，允许对象实现此功能。首先，必须将该对象添加到每个 ROI 图层的观察者列表中。以下命令提供了对这些图层的访问：
IDLcf$Get , /INCLUDE_VIS_CHILDREN, VIS_LAYERS=oVisLayers
变量 oVisLayers 将包含 ENVI 显示中所有可见的图层。要仅获取 ROI，可以遍历其内容，寻找任何 IDLcfVisROINative 的实例。当找到一个时，可以使用以下命令将该对象添加到该 ROI 图层的观察者列表中：
void = oVisLayers[i]->AddObserver(self)
现在对象已添加到观察者列表中，必须添加一个 OnNotify 方法。来自 ROI 图层的任何通知都将发送到此方法。
functionmy_class ::OnNotify, oSubject, strMsg, strArg
输入参数如下：
- oSubject – 发送通知的 ENVI 对象的引用
- strMsg – 包含通知名称的字符串（例如 SETPROPERTY）
- strArg – 包含附加通知信息的字符串（例如 HIDE）
以下是一个独立的示例，演示如何设置一个对象以接收并处理来自 ENVI 图层管理器中 ROI 的通知：
;##############################################################################
; This example demonstrates how to get notifications from ENVI
when changes are
; made to ROIs in the Layer Manager.
;##############################################################################
;------------------------------------------------------------------------------
;+
; Event handler used by XMANAGER
;
; :Params:
; sEvent: in, required, type="struct"
; An IDL event structure
;-
**pro** **roi\_demo\_event**, sEvent
**widget\_control**, sEvent.*top*, GET\_UVALUE=oRoiDemo
oRoiDemo->**Event**, sEvent
**end**
;------------------------------------------------------------------------------
;+
; Checks ENVI for any ROIs. DIsplays all of the ROIs found in
the message
; text box.
;
; :Keywords:
; PREFIX: in, optional, type="string"
; A string or string array of text to be added to the
beginning of the ROI
; message.
;-
**pro** **roi\_demo**::CheckROIs, $
PREFIX=prefix
**compile\_opt** idl2, logical\_predicate
**IDLcf$Get**, /INCLUDE\_VIS\_CHILDREN, VIS\_LAYERS=oVisLayers
name = []
**for** i = **0**, **n\_elements**(oVisLayers)-**1** **do** **begin**
**if** **isa**(oVisLayers[i], 'IDLcfVisROINative') **then** **begin**
void = oVisLayers[i]->**AddObserver**(self)
oROI = oVIsLayers[i]->**GetParameter**('ROI')
**if** **obj\_valid**(oROI) **then** **begin**
name = [name, oROI.*name*]
**endif**
**endif**
**endfor**
**if** (**n\_elements**(prefix) **EQ** **0**) **then** prefix = 'ROIs found:'
str = [prefix,(**n\_elements**(name) **GT** **0**) ? name : 'No ROIs found']
**widget\_control**, **widget\_info**(self.*tlb*, FIND\_BY\_UNAME='text\_message'), SET\_VALUE=str
**end**
;------------------------------------------------------------------------------
;+
; Creates a dialog for displaying information regarding the ENVI
ROIs
;-
**pro** **roi\_demo**::Dialog
**compile\_opt** idl2, logical\_predicate
e = **envi**(/CURRENT)
self.*tlb* = **widget\_base**(/COLUMN, /FLOATING, GROUP\_LEADER=e.*widget\_id*,
$
TITLE='ENVI ROI Demo')
xSize = **100**
wLabel = **widget\_label**(self.*tlb*, /ALIGN\_LEFT, VALUE='Notification
Information')
wText = **widget\_text**(self.*tlb*, UNAME='text\_params', XSIZE=xSize, YSIZE=**3**)
wLabel = **widget\_label**(self.*tlb*, /ALIGN\_LEFT, VALUE='ROI Information')
wText = **widget\_text**(self.*tlb*, UNAME='text\_message', XSIZE=**50**, YSIZE=**10**)
wBase = **widget\_base**(self.*tlb*, /ALIGN\_RIGHT, /ROW)
wButton = **widget\_button**(wBase, UNAME='check\_roi', VALUE='Check ROIs')
**widget\_control**, self.*tlb*, /REALIZE, SET\_UVALUE=self
self->**CheckROIs**
**xmanager**, 'roi\_demo', self.*tlb*, /NO\_BLOCK
**end**
;------------------------------------------------------------------------------
;+
; Event handler for the ROI demo's dialog
;
; :Params:
; sEvent: in, required, type="struct"
; An IDL event structure
;-
**pro** **roi\_demo**::Event, sEvent
**compile\_opt** idl2, logical\_predicate
**case** **widget\_info**(sEvent.**id**, /UNAME) **of**
'check\_roi': self->**CheckROIs**
**else**: **print**, **widget\_info**(sEvent.*id*, /UNAME)
**endcase**
**end**
;------------------------------------------------------------------------------
;+
; Lifecycle method for initializing the object
;
; :Returns:
; 1 if the object initializes successfully and 0 otherwise
;-
**function** **roi\_demo**::Init, $
\_REF\_EXTRA=refExtra
**compile\_opt** idl2, logical\_predicate
**if** (~self->**IDLmiObserver::Init**(\_EXTRA=refextra)) **then** **begin**
**print**, 'Failed to initialize IDLmiObserver'
**return**, **0**
**endif**
**return**, **1**
**end**
;------------------------------------------------------------------------------
;+
; This method is for receiving notifications from the notifiers
for which this
; class is an observer.
;
; :Returns:
; 1
;
; :Params:
; oSubject: in, required, type="objref"
; The ENVI object that is sending the notifications
; strMsg: in, required, type="string"
; The notification string (e.g. SETPROPERTY)
; strArg: in, required, type="string"
; A string containing additional notification information
(e.g. HIDE)
;-
**function** **roi\_demo**::OnNotify, oSubject, strMsg, strArg
**compile\_opt** idl2, logical\_predicate
oSubject->**GetProperty**, NAME=name
**help**, oSubject, OUTPUT=strHelp
**widget\_control**, **widget\_info**(self.*tlb*, FIND\_BY\_UNAME='text\_params'), $
SET\_VALUE=[strHelp, 'STRMSG: '+strMsg, 'STRARG: '+strArg]
str = ''
**case** **strupcase**(strMsg) **of**
'ADDITEMS': **begin**
str = ['Adding a new ROI','Press Check ROIs when finished']
**end**
'REMOVEITEMS': **begin**
self->**CheckROIs**, PREFIX=['ROI has been removed','Remaining ROIs:']
**return**, **1**
**end**
'ROI\_DEFINITION\_CHANGE': **begin**
str = name+' has been updated'
**end**
'SETPROPERTY': **begin**
**case** **strupcase**(strArg) **of**
'COLOR': **begin**
oROI = oSubject->**GetParameter**('ROI')
oROI->**GetProperty**, COLOR=color
str = name+' color changed to '+**strjoin**(**strtrim**(**fix**(color),**2**),',')
**end**
'HIDE': **begin**
oSubject->**GetProperty**, HIDE=hide
str = name+' has been '+(hide ? 'hidden' : 'shown')
**end**
**else**:
**endcase**
**end**
**else**: **print**, 'MESSAGE: '+strMsg
**endcase**
wText = **widget\_info**(self.*tlb*, FIND\_BY\_UNAME='text\_message')
**widget\_control**, **wText**, SET\_VALUE=str
**return**, **1**
**end**
;------------------------------------------------------------------------------
;+
; Class structure definition
;
; :Inherits:
; IDLmiObserver
;
; :Fields:
; tlb: This widget ID of the dialog's top level base.
;-
**pro** **roi\_demo\_\_define**
**compile\_opt** idl2, logical\_predicate
void = {**roi\_demo** $
, **inherits** **IDLmiObserver** $
, *tlb* : **0L** $
}
**end**
;------------------------------------------------------------------------------
;+
;-
**pro** **roi\_demo**
**compile\_opt** idl2, logical\_predicate
e = **envi**(/CURRENT)
**if** ~**isa**(e, 'envi') **then** **begin**
e = **envi**()
eView = e->**GetView**()
file = **Filepath**('qb\_boulder\_msi', ROOT\_DIR=e.*root\_dir*,
SUBDIRECTORY=['data'])
eRaster = e->**OpenRaster**(file)
eLayer = eView->**CreateLayer**(eRaster)
file = **Filepath**('qb\_boulder\_roi.xml', ROOT\_DIR=e.*root\_dir*,
SUBDIRECTORY=['data'])
eROI = e->**OpenROI**(file)
nROI = **n\_elements**(eROI)
eLayerROI = **objarr**(nROI)
**for** i = **0**, nROI-**1** **do** **begin**
eLayerROI[i] = eLayer->**AddROI**(eROI[i])
**endfor**
**endif**
oROIDemo = **obj\_new**('roi\_demo')
oROIDemo->**Dialog**
**end**