錯誤PyObjC

Question

我試圖覆蓋使用PyObjC一些文本的圖像NSImage中繪製文本，同時努力回答我的問題，"Annotate images using tools built into OS X"。通過引用CocoaMagic，一個RubyObjC更換爲RMagick，我想出了這一點：

#!/usr/bin/env python 

from AppKit import * 

source_image = "/Library/Desktop Pictures/Nature/Aurora.jpg" 
final_image = "/Library/Desktop Pictures/.loginwindow.jpg" 
font_name = "Arial" 
font_size = 76 
message = "My Message Here" 

app = NSApplication.sharedApplication() # remove some warnings 

# read in an image 
image = NSImage.alloc().initWithContentsOfFile_(source_image) 
image.lockFocus() 

# prepare some text attributes 
text_attributes = NSMutableDictionary.alloc().init() 
font = NSFont.fontWithName_size_(font_name, font_size) 
text_attributes.setObject_forKey_(font, NSFontAttributeName) 
text_attributes.setObject_forKey_(NSColor.blackColor, NSForegroundColorAttributeName) 

# output our message 
message_string = NSString.stringWithString_(message) 
size = message_string.sizeWithAttributes_(text_attributes) 
point = NSMakePoint(400, 400) 
message_string.drawAtPoint_withAttributes_(point, text_attributes) 

# write the file 
image.unlockFocus() 
bits = NSBitmapImageRep.alloc().initWithData_(image.TIFFRepresentation) 
data = bits.representationUsingType_properties_(NSJPGFileType, nil) 
data.writeToFile_atomically_(final_image, false) 

當我運行它，我得到這個：

Traceback (most recent call last): 
    File "/Users/clinton/Work/Problems/TellAtAGlance/ObviouslyTouched.py", line 24, in <module> 
    message_string.drawAtPoint_withAttributes_(point, text_attributes) 
ValueError: NSInvalidArgumentException - Class OC_PythonObject: no such selector: set 

尋找在文檔的drawAtPoint：withAttributes：它說，「你應該只在NSView有焦點時調用這個方法。」 NSImage不是NSView的子類，但我希望這可以工作，並且在Ruby示例中似乎非常類似。

我需要做些什麼才能完成這項工作？

---

我重寫了代碼，將它轉換爲行，換行爲Objective-C基礎工具。它工作，沒有問題。 [我會很高興在這裏後，如果如果有一個這樣做的原因。]

的問題就變成了，如何：

[message_string drawAtPoint:point withAttributes:text_attributes]; 

從

message_string.drawAtPoint_withAttributes_(point, text_attributes) 

有什麼不同？有沒有辦法告訴哪個「OC_PythonObject」引發NSInvalidArgumentException？

Answer 1

下面是在上面的代碼中的問題：

text_attributes.setObject_forKey_(NSColor.blackColor, NSForegroundColorAttributeName) 
-> 
text_attributes.setObject_forKey_(NSColor.blackColor(), NSForegroundColorAttributeName) 

bits = NSBitmapImageRep.alloc().initWithData_(image.TIFFRepresentation) 
data = bits.representationUsingType_properties_(NSJPGFileType, nil) 
-> 
bits = NSBitmapImageRep.imageRepWithData_(image.TIFFRepresentation()) 
data = bits.representationUsingType_properties_(NSJPEGFileType, None) 

小錯別字確實如此。

注意，代碼的中間部分可以用這個更可讀的變體所取代：

# prepare some text attributes 
text_attributes = { 
    NSFontAttributeName : NSFont.fontWithName_size_(font_name, font_size), 
    NSForegroundColorAttributeName : NSColor.blackColor() 
} 

# output our message 
NSString.drawAtPoint_withAttributes_(message, (400, 400), text_attributes) 

我通過查看源代碼NodeBox，十二行psyphography.py和cocoa.py瞭解到這一點，特別是save和_getImageData方法。