C语言详细讲解注释符号的如何使用

一、注释规则 编译器在编译过程中使用空格替换整个注释字符串字面量中的 和 * * 不代表注释符号 * * 型注释不能被嵌套 下面看一下

一、注释规则

  • 编译器在编译过程中使用空格替换整个注释
  • 字符串字面量中的 // 和 /*...*/ 不代表注释符号
  • /*......*/ 型注释不能被嵌套

下面看一下这样一段代码:

#include <stdio.h>
 
int main()
{
    int/*...*/i;
 
    char* s = "abcdefgh      //hijklmn";
    
    //Is it a \
    valid comment?
    
    in/*...*/t i;
    
    return 0;
}

下面为编译结果,可以看到只有 12 行报错:

下面按照编译规则对代码进行一下改进:

#include <stdio.h>
 
int main()
{
    int i;
 
    char* s = "abcdefgh      //hijklmn";
    
    in t i;
    
    return 0;
}

所以说当然 in/*...*/t i; 会报错。

二、注释中一个有趣的问题

y=x/*p是什么意思?

作者本意:把 × 除以 *p 的结果赋值给y 。

编译器:将 /* 作为一段注释的开始,把 /* 后的内容都当成注释内容,直到 */ 出现为止。

在编译器看来,注释和其它程序元素是平等的。因此,作为工程师不能轻视注释。

#include<stdio.h>
 
int main()
{
    int y = 1;
    int x = 2;
    int* p = &x;
    
    y = x/*p;
    
    return 0;
}

编译结果和预想的一样会报错:

解决办法就是在 * 和 / 中间加上空格就好。

#include<stdio.h>
 
int main()
{
    int y = 1;
    int x = 2;
    int* p = &x;
    
    y = x / *p;
    
    return 0;
}

三、教科书型注释

这种注释每一行都解释程序的运行过程,没有很大的意义,注释用于阐述原因和意图而不是描述程序的运行过程!

四、迷惑型的注释

写注释不是晒心情,必须无二义性,起到对代码进行提示的作用,避免使用缩写!

五、忽悠型注释

注释是对代码的提示,避免臃肿和喧宾夺主。

六、搞笑型注释

佛祖是佛学专业的大师,但是没学过编程,因此保佑不了你,你只能靠自己避开BUG。

七、漂亮的程序注释

下面为一个高通公司写的一段代码,不管是语句的注释,还是函数的注释,还是整体代码风格,都看起来非常舒服。

/*
  ========================================================================
  FILE:  Form.c
  
  SERVICES:  
  GENERAL DESCRIPTION: Concrete implementation of RootForm and base IForm
  methods
  ========================================================================
  ========================================================================
    
               Copyright ?1999-2005 QUALCOMM Incorporated 
                     All Rights Reserved.
                   QUALCOMM Proprietary/GTDR
    
  ========================================================================
  ========================================================================
*/
 
 
/*==================================================================================
                         XXXXXXX Confidential Proprietary
                   (c) Copyright XXXXXXX - All Rights Reserved
Revision History:
                         Modification
  Author                     Date        CR Number      Major Changes
----------------------   ------------   ------------   ----------------------------
Daniel Rossler            01/18/2007     LIBkk94550    Add check for NULL pointers
                                                       in order to avoid a panic
==================================================================================*/
 
 
 
#include "FormBase.h"
 
#include "AEESoftkeyWidget.h"
#include "AEEImageWidget.h"
#include "AEEStaticWidget.h"
#include "AEEImageStaticWidget.h"
#include "AEERootContainer.h"
#include "AEEWProperties.h"
#include "AEEVectorModel.h"
 
#include "AEEWeb.h"
 
#include "AEERootForm.h"
#include "AEEResFile.h"
 
#include "FormUtil.h"
#include "AEEDisplayCanvas.h"
 
#define FORMSTACK_MIN  10
#define FORMSTACK_GROW 2
 
/
// RootForm
 
typedef struct RootForm {
   Form              base;
 
   IRootContainer *  piContainer;
   AEERect           rcContainer;
   AEERect           rcClient;
 
   IVectorModel *    piForms;
   ModelListener     mlFormActive;
   ModelListener     mlFormTopmostNonPopup;
 
   IWidget *         piTitle;
   ImageStaticInfo   titleInfo;
   IWidget *         piSoftkeys;
   IWidget *         piBackground;
 
   IWidget *         piActiveWidget;  
 
   IResFile *        piThemeFile;
   const char *      themeFile;
} RootForm;
 
#define DECL(c) c* me = (c *)po
 
static __inline IForm *ROOTFORM_TO_IFORM(RootForm *me) {
   return (IForm *)me;
}
 
static __inline Form *ROOTFORM_TO_FORM(RootForm *me) {
   return (Form *)me;
}
 
static __inline IRootForm *ROOTFORM_TO_IROOTFORM(RootForm *me) {
   return (IRootForm *)me;
}
 
static void RootForm_FreeFormEntry(IForm *po)
{
   IFORM_Release(po);
}
 
static void RootForm_UpdateClientArea(RootForm *me)
{
   WidgetPos pos;
   WExtent titleExtent, skExtent;
 
   if (me->piSoftkeys) {
      IWIDGET_GetExtent(me->piSoftkeys, &skExtent);
 
      // Adjust softkey position based on current height
      IROOTCONTAINER_GetPos(me->piContainer, me->piSoftkeys, &pos);
      pos.y = me->rcContainer.dy - skExtent.height;
      IROOTCONTAINER_SetPos(me->piContainer, me->piSoftkeys, WIDGET_ZNORMAL, &pos);
   } else {
      SETWEXTENT(&skExtent, 0, 0);
   }
 
   if (me->piTitle) {
      IWIDGET_GetExtent(me->piTitle, &titleExtent);
   } else {
      SETWEXTENT(&titleExtent, 0, 0);
   }
   
   // Calculate client area
   SETAEERECT(&me->rcClient, 0, titleExtent.height,
              me->rcContainer.dx,
              me->rcContainer.dy - skExtent.height - titleExtent.height);
}
 
 
static void RootForm_UpdateTheme(RootForm *me, const char *baseName)
{
   WExtent wextent;
 
   BUIT_LOG("FORMS EVT: Update Theme Started for %s", baseName);
 
   if (!me->piThemeFile)
      return;
 
   if (me->piTitle) {
      IWIDGET_SetProperties(me->piTitle, me->piThemeFile, baseName, "Title", "Properties", 0);
      IWIDGET_GetPreferredExtent(me->piTitle, &wextent);
      wextent.width = me->rcContainer.dx;
      IWIDGET_SetExtent(me->piTitle, &wextent);
   }
 
   if (me->piSoftkeys) {
      IWIDGET_SetProperties(me->piSoftkeys, me->piThemeFile, baseName, "Softkeys", "Properties", 0);
      IWIDGET_GetPreferredExtent(me->piSoftkeys, &wextent);
      wextent.width = me->rcContainer.dx;
      IWIDGET_SetExtent(me->piSoftkeys, &wextent);
   }
 
   if (me->piBackground) {
      IWIDGET_SetProperties(me->piBackground, me->piThemeFile, baseName, "Background", "Properties", 0);
   }
 
   // Update client area since sizes may have changed
   RootForm_UpdateClientArea(me);
 
   BUIT_LOG("FORMS EVT: Update Theme Finished for %s", baseName);
}
 
// updates the rootform with the background image, softkey and 
// title text of the TOS form.
static void RootForm_Update(RootForm *me, uint32 dwItemMask, IForm* piForm)
{
   boolean bPopup = 0;
 
   // get form's popup flag
   bPopup = IFORM_GetIsPopup(piForm);
 
   // if the form's widget has changed, update the scroll model
   // for the scroll indicator in the softkey widget
   if (dwItemMask & FORMITEM_WIDGET) {
      
      IWidget *piWidget = NULL;
      // get form's widget
      IFORM_GetWidget(piForm, WID_FORM, &piWidget);
 
      // update the widget and the scroll model
      if (piWidget) {
 
         // if the active widget has been changed underneath us...
         
         if (me->piActiveWidget && piWidget != me->piActiveWidget) {
            // this block will only be executed when the form widget is changed
            // by the application logic while the form is active
            WidgetPos pos;
            WExtent we;
   
            IWIDGET_MoveFocus(FORM_WIDGET(me), (IWidget*)WIDGET_FOCUS_NONE);
   
            IWIDGET_GetExtent(me->piActiveWidget, &we);
            IWIDGET_SetExtent(piWidget, &we);
   
            // remove the previously active widget from the root container
            if (AEE_SUCCESS == IROOTCONTAINER_GetPos(me->piContainer, me->piActiveWidget, &pos)) {
               IROOTCONTAINER_Remove(me->piContainer, me->piActiveWidget);
            }
            
            // add the new widget to the root container
            IROOTCONTAINER_Insert(me->piContainer, piWidget, WIDGET_ZTOPMOST, &pos);
            // and remember it fondly
            RELEASEIF(me->piActiveWidget);
            me->piActiveWidget = piWidget;
            ADDREFIF(piWidget);
 
            // set focus to the new widget
            IWIDGET_MoveFocus(FORM_WIDGET(me), piWidget);
         
         } else if (!me->piActiveWidget) {
            me->piActiveWidget = piWidget;
            ADDREFIF(piWidget);
         }
 
      }
 
      RELEASEIF(piWidget);
   }
 
 
   // if the form's background image has changed...
   // if form is a popup, then retain the background image 
   // from the previous form
   if (dwItemMask & FORMITEM_BACKGROUND && me->piBackground && !bPopup) {      
      IImage *pii = NULL;
      
      // Try to grab the image from the new form.  
      IFORM_GetBGImage(piForm, &pii);
 
      // If non-existent, try defaulting to the root form
      if (!pii) IFORM_GetBGImage(ROOTFORM_TO_IFORM(me), &pii);
      
      // Apply the result (NULL or otherwise) to our background widget
      IWIDGET_SetImage(me->piBackground, pii);
      RELEASEIF(pii);
   }
   
   // if the form's title text has changed...  retain previous title
   // if we are a popup 
 
   if ((dwItemMask & FORMITEM_TITLE) && me->piTitle && !bPopup) {
      // Release image. Text is owned by form
      RELEASEIF(me->titleInfo.piImage);
      IFORM_GetTextPtr(piForm, FID_TITLE, &me->titleInfo.pwText);
      IFORM_GetTitleImage(piForm, &me->titleInfo.piImage);
 
      // Set title info
      IWIDGET_SetImageStaticInfo(me->piTitle, &me->titleInfo, 0);
   }
 
   // if the form's softkey text has changed...
   if ((dwItemMask & FORMITEM_SOFTKEY) && me->piSoftkeys) {
 
      IForm* piTopForm = IROOTFORM_GetTopForm(ROOTFORM_TO_IROOTFORM(me));
 
      AECHAR *pwsz = NULL;
      IWidget *piKey = NULL;
 
      if (piTopForm == piForm) {
         // set softkey 1 text
         IFORM_GetTextPtr(piForm, FID_SOFTKEY1, &pwsz);
         if (AEE_SUCCESS == IWIDGET_GetSoftkey(me->piSoftkeys, PROP_SOFTKEY1, &piKey)) {
            IWIDGET_SetText(piKey, pwsz, 0);
         }
         RELEASEIF(piKey);
   
         // set softkey 2 text
         IFORM_GetTextPtr(piForm, FID_SOFTKEY2, &pwsz);
         if (AEE_SUCCESS == IWIDGET_GetSoftkey(me->piSoftkeys, PROP_SOFTKEY2, &piKey)) {
            IWIDGET_SetText(piKey, pwsz, 0);
         }
      }
      RELEASEIF(piKey);
   }
 
   if ((dwItemMask & FORMITEM_THEME_BASENAME)) {
      char *baseName = 0;
 
      IFORM_GetThemeBaseName(piForm, &baseName);
      RootForm_UpdateTheme(me, baseName);
   }
 
}
 
static boolean RootForm_ReplaceWidget(RootForm *me, IWidget **piw, IWidget *piwNew, IWidget *piwBefore)
{
   int        result = AEE_SUCCESS;
   WidgetPos  pos;
 
   if (*piw) {
      (void) IROOTCONTAINER_GetPos(me->piContainer, *piw, &pos);
      (void) IROOTCONTAINER_Remove(me->piContainer, *piw);
      IWIDGET_Release(*piw);
   }
 
   if (piwNew) {
      result = IROOTCONTAINER_Insert(me->piContainer, piwNew, piwBefore, &pos);
      
      if (result == AEE_SUCCESS) {
         IWIDGET_AddRef(piwNew);
      } else {
         piwNew = NULL;
      }
   }
 
   *piw = piwNew;
 
   // Do an update since extents may have changed
   RootForm_UpdateClientArea(me);
 
   return (AEE_SUCCESS == result);
}
 
static int RootForm_SetThemeName(RootForm *me, const char *themeFile)
{
   if (!me->piThemeFile)
      return EBADSTATE;
   
   FREEIF(me->themeFile);
   me->themeFile = STRDUP(themeFile);
   
   IRESFILE_Close(me->piThemeFile);
   if (themeFile)
      return IRESFILE_Open(me->piThemeFile, themeFile);
   else
      return AEE_SUCCESS;
}
 
static int RootForm_SetDisplay(RootForm *me, IDisplay *piDisplay)
{
   int nErr = AEE_SUCCESS;
   IDisplayCanvas *piCanvas = 0;
 
   nErr = ISHELL_CreateInstance(FORM_SHELL(me), AEECLSID_DISPLAYCANVAS, (void **)&piCanvas);
      
   if (!nErr) {
      WExtent extent;
      WidgetPos pos;
      
 
      IDISPLAY_SetClipRect(piDisplay, NULL); // reset the clipping rectangle
      IDISPLAY_GetClipRect(piDisplay, &me->rcContainer);
      SETAEERECT(&me->rcClient, 0, 0, me->rcContainer.dx, me->rcContainer.dy);
 
      IDISPLAYCANVAS_SetDisplay(piCanvas, piDisplay);
      IROOTCONTAINER_SetCanvas(me->piContainer, (ICanvas *)piCanvas, &me->rcContainer);
 
      if (me->piTitle) {
         // Set extent, title is already positioned at 0, 0
         IWIDGET_GetExtent(me->piTitle, &extent);
         extent.width = me->rcContainer.dx;
         IWIDGET_SetExtent(me->piTitle, &extent);
      }
 
      if (me->piBackground) {
         // Set extent, background is already positioned at 0, 0
         extent.width = me->rcContainer.dx;
         extent.height = me->rcContainer.dy;
         IWIDGET_SetExtent(me->piBackground, &extent);
      }
 
      if (me->piSoftkeys) {
         // Set extent
         IWIDGET_GetExtent(me->piSoftkeys, &extent);
         extent.width = me->rcContainer.dx;
         IWIDGET_SetExtent(me->piSoftkeys, &extent);
         // And position at bottom of screen
         IROOTCONTAINER_GetPos(me->piContainer, me->piSoftkeys, &pos);
         pos.y = me->rcContainer.dy - extent.height;
         IROOTCONTAINER_SetPos(me->piContainer, WIDGET_ZNORMAL, me->piSoftkeys, &pos);
      }
   }
 
   RELEASEIF(piCanvas);
 
   return nErr;
}
 
 
static void RootForm_ApplyTheme(RootForm *me)
{
   int nrForms, i;
 
   if (!me->piThemeFile) 
      return;
   
   nrForms = IVECTORMODEL_Size(me->piForms);
   for (i = 0; i < nrForms; i++) {
      IForm *piForm;
      char* pTheme = 0;
      IVECTORMODEL_GetAt(me->piForms, i, (void **)&piForm);
      
      IFORM_GetThemeBaseName(ROOTFORM_TO_IFORM(me), &pTheme);
      pTheme = (pTheme) ? pTheme : "(None)";
      
      BUIT_LOG("FORMS EVT: Apply Theme Started for %s", pTheme);
      
      IFORM_ApplyTheme(piForm);
      
      BUIT_LOG("FORMS EVT: Apply Theme Finished for %s", pTheme);
   }
 
   if (nrForms == 0) {
      char *baseName = 0;
      
      IFORM_GetThemeBaseName(ROOTFORM_TO_IFORM(me), &baseName);
#ifdef FEATURE_MOT_BREW
      if (baseName != NULL) {
	      RootForm_UpdateTheme(me, baseName);
      }
#else
      RootForm_UpdateTheme(me, baseName);
#endif /*FEATURE_MOT_BREW*/
   }
}
 
boolean RootForm_HandleEvent(IRootForm *po, AEEEvent evt, uint16 wParam, uint32 dwParam)
{
   DECL(RootForm);
 
   if (FORM_WIDGET(me)
      && IWIDGET_HandleEvent(FORM_WIDGET(me), evt, wParam, dwParam))
      return TRUE;
 
   if (evt == EVT_WDG_GETPROPERTY) {
      switch(wParam) {
      case FID_THEME_FNAME:
         *(const char **)dwParam = me->themeFile;
         return TRUE;
 
      case FID_THEME_FILE:
         *(IResFile **)dwParam = me->piThemeFile;
         ADDREFIF(me->piThemeFile);
         return TRUE;
 
      case WID_TITLE:
         *(IWidget **)dwParam = me->piTitle;
         ADDREFIF(me->piTitle);
         return TRUE;
 
      case WID_SOFTKEYS:
         *(IWidget **)dwParam = me->piSoftkeys;
         ADDREFIF(me->piSoftkeys);
         return TRUE;
 
      case WID_BACKGROUND:
         *(IWidget **)dwParam = me->piBackground;
         ADDREFIF(me->piBackground);
         return TRUE;
 
      case WID_FORM:
         IROOTCONTAINER_QueryInterface(me->piContainer, AEEIID_WIDGET, (void **)dwParam);
         return TRUE;
 
      case WID_CONTAINER:
         *(IContainer **)dwParam = IROOTCONTAINER_TO_ICONTAINER(me->piContainer);
         ADDREFIF(me->piContainer);
         return TRUE;
 
      default:
         // Fall back on formbase
         return Form_HandleEvent(ROOTFORM_TO_IFORM(me), evt, wParam, dwParam);
      }
 
   } else if (evt == EVT_WDG_SETPROPERTY) {
      IForm *piForm = 0;
 
      switch(wParam) {
      case FID_ACTIVE:
         piForm = IROOTFORM_GetTopForm(po);
         if (piForm) {
            // Activate or de-activate the top form
            IFORM_SetProperty(piForm, FID_ACTIVE, dwParam);
         }
         // and invalidate root container on activation
         if ((boolean)dwParam) {
            IROOTCONTAINER_Invalidate(me->piContainer, 0, 0, 0);
         }
         return TRUE;
 
      case FID_THEME:
         RootForm_ApplyTheme(me);
         return TRUE;
 
      case FID_THEME_FNAME:
         if (AEE_SUCCESS == RootForm_SetThemeName(me, (const char *)dwParam)) {
            RootForm_ApplyTheme(me);
            return TRUE;
         }
         return FALSE;
 
      case FID_BACKGROUND:
         // If we have a background widget, set the image into it
         if (me->piBackground) {
            IWIDGET_SetFormImage(me->piBackground, FORM_SHELL(me), (FormRes *)dwParam);
         }
         // Also load the image into our internal form, which will hold it as a default for other forms
         return Form_HandleEvent(ROOTFORM_TO_IFORM(me), evt, wParam, dwParam);
 
      case FID_DISPLAY:
         return AEE_SUCCESS == RootForm_SetDisplay(me, (IDisplay *)dwParam);
 
      case FID_WPROPS: {
         WPropDesc *pdesc = (WPropDesc *)dwParam;
         WResPropDesc wd;
                  
         wd.piResFile = me->piThemeFile;
         if (pdesc) {
            wd.args = pdesc->args;
            wd.piWidget = pdesc->piWidget;
         }
         return IWIDGET_SetProperty(pdesc->piWidget, PROP_APPLYWPROPS, (uint32)&wd);
      }
 
      case WID_TITLE:
         return RootForm_ReplaceWidget(me, &me->piTitle, (IWidget *)dwParam, WIDGET_ZNORMAL);
 
      case WID_SOFTKEYS:
         return RootForm_ReplaceWidget(me, &me->piSoftkeys, (IWidget *)dwParam, WIDGET_ZNORMAL);
 
      case WID_BACKGROUND:
         return RootForm_ReplaceWidget(me, &me->piBackground, (IWidget *)dwParam, WIDGET_ZBOTTOMMOST);
 
      default:
         // Fall back on formbase
         return Form_HandleEvent(ROOTFORM_TO_IFORM(me), evt, wParam, dwParam);
      }
   }
 
   // Non get/set property events are sent on to the topmost form
   {
      IForm *piForm = IROOTFORM_GetTopForm(po);
      if (!piForm)
         return FALSE;
      else
         return IFORM_HandleEvent(piForm, evt, wParam, dwParam);
   }  
}
 
 
static void RootForm_UpdateActiveListenerCB(RootForm *me, FormEvent *pEvent)
{
   if (pEvent->base.evCode == EVT_MDL_FORM_CHANGE) {
      RootForm_Update(me, pEvent->dwItemMask, pEvent->piForm);
   }
}
 
static void RootForm_UpdateTopmostNonPopupListenerCB(RootForm *me, FormEvent *pEvent)
{
   uint32 dwItemMask = pEvent->dwItemMask & (FORMITEM_BACKGROUND | FORMITEM_TITLE | FORMITEM_SOFTKEY);
 
   if (pEvent->base.evCode == EVT_MDL_FORM_CHANGE && dwItemMask) {
      RootForm_Update(me, dwItemMask, pEvent->piForm);
   }
}
 
static void RootForm_ShowFormWidget(IRootForm *po, IForm *piForm, boolean bShow, boolean bFocus)
{
   DECL(RootForm);
   WidgetPos pos;
   IWidget *piWidget;
 
   if (!piForm)
      return;
 
   IFORM_GetWidget(piForm, WID_FORM, &piWidget);
   
   if (!piWidget)
      return;
 
   // Set visibility 
   IROOTCONTAINER_GetPos(me->piContainer, piWidget, &pos);
   pos.bVisible = bShow;
   IROOTCONTAINER_SetPos(me->piContainer, piWidget, WIDGET_ZNORMAL, &pos);
 
   // and set focus to the widget
   if (bShow && bFocus) {
      IWIDGET_MoveFocus(FORM_WIDGET(me), piWidget);
   } else {
      IWIDGET_MoveFocus(FORM_WIDGET(me), WIDGET_FOCUS_NONE);
   }
   
   IWIDGET_Release(piWidget);
}
 
 
/** Activates a given form.  Previous form should have been
 deactivated before this is called with bActivate set
 */
static void RootForm_ActivateForm(IRootForm *po, IForm *piForm, boolean bActivate)
{
   DECL(RootForm);
 
   if (!piForm)
      return;
 
   if (bActivate) {
      // Undo the currently known active widget
      RELEASEIF(me->piActiveWidget);
      IFORM_GetWidget(piForm, WID_FORM, &me->piActiveWidget);
      // Then go update all the items except the forms widget as this is not the 
      // form updating its own widget. Need to update first since theme information
      // affect client area which affects form activation
      RootForm_Update(me, FORMITEM_ALL & ~FORMITEM_WIDGET, piForm);
      // then activate
      IFORM_Activate(piForm);
   } else {
      IFORM_Deactivate(piForm);
   }
}
 
static int RootForm_GetFormIndex(RootForm *me, IForm **ppiForm) 
{
   IForm *piForm;
   int nrForms;
 
   nrForms = IVECTORMODEL_Size(me->piForms);
 
   if (nrForms > 0) {
 
      if (*ppiForm == FORM_LAST || *ppiForm == FORM_DEFAULT) {
 
         IVECTORMODEL_GetAt(me->piForms, nrForms - 1, (void **)ppiForm);
         return nrForms - 1;
 
      } else if (*ppiForm == FORM_FIRST) {
 
         IVECTORMODEL_GetAt(me->piForms, 0, (void **)ppiForm);
         return 0;
 
      } else {
 
         int i;
         for (i = 0; i < nrForms; i++) {
            IVECTORMODEL_GetAt(me->piForms, i, (void **)&piForm);
            if (piForm == *ppiForm)
               return i;
         }
 
      }
   }
 
   return -1;
}
 
static __inline int RootForm_GetFormInsertionIndex(RootForm *me, IForm **ppiForm)
{
   int delta;
 
   if (*ppiForm == FORM_FIRST)
      return 0;
 
   if (*ppiForm == FORM_LAST || *ppiForm == FORM_DEFAULT) {
      delta = 1;
   } else {
      delta = 0;
   }
 
   return RootForm_GetFormIndex(me, ppiForm) + delta;
}
 
static void RootForm_StackChange(IRootForm *po)
{
   DECL(RootForm);
   IForm* piTopForm = IROOTFORM_GetTopForm(po);
   
   LISTENER_Cancel(&me->mlFormActive);
   LISTENER_Cancel(&me->mlFormTopmostNonPopup);
 
   // If there are still forms on the stack, then we need to set up several things:
   //   1. The topmost form is the active form
   //   2. All other forms are not active
   //   3. The topmost form is being listened to via mlFormActive
   //   4. The topmost non-popup form is being listened to via mlFormTopmostNonPopup
   //   5. The topmost non-popup form and all popup forms on top of it are shown
   //   6. Forms below the topmost non-popup form are now shown
   if (piTopForm)
   {
      boolean bFoundTopmostNonPopup = FALSE;
      IModel* piModel = NULL;
      IForm*  pif;
 
      // Logging stack change begin
      BUIT_LOG("FORMS EVT: Stack Change Starting...", 1);
 
      // Need to deal with the non-active forms first, then the active form
      for (pif = piTopForm; pif; pif = IROOTFORM_GetForm(po, pif, FALSE, FALSE))
      {
         boolean bPopup;
 
         bPopup = IFORM_GetIsPopup(pif);
         IFORM_GetFormModel(pif, &piModel);
         if (piModel)
         {
            if (pif != piTopForm)
            {
               RootForm_ShowFormWidget(po, pif, (boolean)(bFoundTopmostNonPopup? FALSE : TRUE), FALSE);
               if (IFORM_IsActive(pif))
               {
                  RootForm_ActivateForm(po, pif, FALSE);
               }
            }
 
            if (!bPopup && !bFoundTopmostNonPopup)
            {
               IMODEL_AddListenerEx(piModel, &me->mlFormTopmostNonPopup, (PFNLISTENER)RootForm_UpdateTopmostNonPopupListenerCB, me);
               if (pif != piTopForm)
                  // Only update if not the topmost form since the
                  // Activate below applies theme again The topmost
                  // non-popup (but not the top!) influences the
                  // background, title ans associated themes
                  RootForm_Update(me, FORMITEM_BACKGROUND | FORMITEM_TITLE | FORMITEM_THEME_BASENAME, pif);
               bFoundTopmostNonPopup = TRUE;
            }
         }
         RELEASEIF(piModel);
      }
 
      RootForm_ActivateForm(po, piTopForm, TRUE);
      RootForm_ShowFormWidget(po, piTopForm, TRUE, TRUE);
      IFORM_GetFormModel(piTopForm, &piModel);
      if (piModel)
         IMODEL_AddListenerEx(piModel, &me->mlFormActive, (PFNLISTENER)RootForm_UpdateActiveListenerCB, me);
      RELEASEIF(piModel);
      
      // Log that the form is about to be activated - all theme stuff has happened by now)
      BUIT_LOG("FORMS EVT: Stack Change Finished", 1);
 
   }
 
    // Notify change in stack
   Form_Notify(ROOTFORM_TO_FORM(me), FORMITEM_STACK);
}
 
 
int RootForm_InsertForm(IRootForm *po, IForm *piForm, IForm *pifBefore)
{
   DECL(RootForm);
   IWidget *piWidget = 0;
   IWidget *piwBefore = 0;
   IForm *pifCurrent;
   int nrForms, formIndex, nErr;
 
   if (!piForm)
      return EBADPARM;
 
   // Make sure we can insert, get the index we want to insert at
   formIndex = RootForm_GetFormInsertionIndex(me, &pifBefore);
 
   if (formIndex < 0)
      return EBADPARM;
 
   nrForms = IVECTORMODEL_Size(me->piForms);
   pifCurrent = IROOTFORM_GetTopForm(po);
 
   // Get widget to insert
   IFORM_GetWidget(piForm, WID_FORM, &piWidget);
 
   // Get widget insertion point. 
   if (formIndex == nrForms || !nrForms) {
      piwBefore = WIDGET_ZTOPMOST;
   } else if (pifBefore == FORM_FIRST) {
      if (me->piBackground != NULL) {
     
         // If we have a background widget, try to insert the form's widget
         // above the background widget
         piwBefore = IROOTCONTAINER_GetWidget(me->piContainer, me->piBackground, TRUE, FALSE);
         if (piwBefore) {
            // Add a reference, so it can be released below.
            IWIDGET_AddRef(piwBefore);
         }
      } 
 
      if (!piwBefore) {
         // No background widget, insert the form's widget at the bottom.
         piwBefore = WIDGET_ZBOTTOMMOST;
      }
 
   } else {
      IFORM_GetWidget(pifBefore, WID_FORM, &piwBefore);
   }
 
   // Make sure we have space for the new form
   nErr = IVECTORMODEL_EnsureCapacity(me->piForms, MAX(FORMSTACK_MIN, nrForms + 1), FORMSTACK_GROW);
 
   // Now insert
   if (!nErr && piWidget && piwBefore) {
      WidgetPos pos;
 
      // Not really needed here since Activate does this to, but since
      // we need to give a position on insert we may as well do it
      // right
      pos.x = me->rcClient.x; 
      pos.y = me->rcClient.y;
      pos.bVisible = (piwBefore == WIDGET_ZTOPMOST);
      
      // Insert widget into widget stack
      nErr = IROOTCONTAINER_Insert(me->piContainer, piWidget, piwBefore, &pos);
   }
 
   if (!nErr) {
      char* pTheme = 0;
 
      // Add form to formstack
      IVECTORMODEL_InsertAt(me->piForms, formIndex, piForm);
      IFORM_AddRef(piForm);
 
      // Set rootform
      IFORM_SetProperty(piForm, FID_ROOT, (uint32)po);
 
      // Log info
      IFORM_GetThemeBaseName(ROOTFORM_TO_IFORM(me), &pTheme);
      pTheme = (pTheme) ? pTheme : "(None)";
 
      BUIT_LOG("FORMS EVT: Insert Set Theme Started for %s", pTheme);
 
      // Set theme on new form
      IFORM_ApplyTheme(piForm);
 
      BUIT_LOG("FORMS EVT: Insert Set Theme Finished for %s", pTheme);
      //RootForm_Update(me, FORMITEM_THEME, piForm);
 
      RootForm_StackChange(po);
 
}
 
   RELEASEIF(piWidget);
   if (piwBefore != WIDGET_ZTOPMOST && piwBefore != WIDGET_ZBOTTOMMOST)
      RELEASEIF(piwBefore);
   return nErr;
}
 
int RootForm_RemoveForm(IRootForm *po, IForm *piForm)
{
   DECL(RootForm);
   IWidget *piWidget = 0;
   IForm *piF = 0;
   int nrForms = 0;
   int formIndex;
   boolean bOnlyPopups = 1;
 
   if (me->piForms)
      nrForms = IVECTORMODEL_Size(me->piForms);
 
   if (piForm == FORM_ALL) {
      while (nrForms > 0) {
         IROOTFORM_RemoveForm(po, FORM_LAST);
         nrForms = IVECTORMODEL_Size(me->piForms);
      }
 
   } else {
      formIndex = RootForm_GetFormIndex(me, &piForm);
      
      if (formIndex < 0)
         return EBADPARM;
      
      IFORM_GetWidget(piForm, WID_FORM, &piWidget);
      
      if (piWidget) {
         IROOTCONTAINER_Remove(me->piContainer, piWidget);
      }
      
      // Hide form widget
      RootForm_ShowFormWidget(po, piForm, FALSE, FALSE);
      // Deactivate form
      RootForm_ActivateForm(po, piForm, FALSE);
      // Tell it of rootform departure
      IFORM_SetProperty(piForm, FID_ROOT, 0);
      // Delete it from the stack
      IVECTORMODEL_DeleteAt(me->piForms, formIndex);
 
      RootForm_StackChange(po);
 
      RELEASEIF(piWidget);
 
      // Now many forms do we now have?
      nrForms = IVECTORMODEL_Size(me->piForms);
   }
 
   // Cycle through remaining forms to determine type
   for (piF = IROOTFORM_GetTopForm(po); piF && bOnlyPopups; piF = IROOTFORM_GetForm(po, piF, FALSE, FALSE))
   {
      bOnlyPopups &= IFORM_GetIsPopup(piF);
   }  
 
 
   if ((0 == nrForms) || bOnlyPopups)
   {
      // If we don't have any more forms, or the only forms we do have are popups, 
      // ensure the title has been cleaned (the title memory is owned by the last full screen form, 
      // which may no longer exist).
      if (me->piTitle) {
         // Release image. Text is owned by form
         RELEASEIF(me->titleInfo.piImage);
         me->titleInfo.pwText = NULL;
 
         // Set title info
         IWIDGET_SetImageStaticInfo(me->piTitle, &me->titleInfo, 0);
      }
   }
 
   if (0 == nrForms) {
      
      // There are no more forms, ensure the softkey labels
      // have been cleaned (the softkey memory is owned by the form, which may no 
      // longer exist).
      if (me->piSoftkeys) {
         IWidget *piKey = NULL;
 
         (void) IWIDGET_GetSoftkey(me->piSoftkeys, PROP_SOFTKEY1, &piKey);
         if (piKey) {
            IWIDGET_SetText(piKey, NULL, 0);
            IWIDGET_Release(piKey);
            piKey = NULL;
         }
 
         (void) IWIDGET_GetSoftkey(me->piSoftkeys, PROP_SOFTKEY2, &piKey);
         if (piKey) {
            IWIDGET_SetText(piKey, NULL, 0);
            IWIDGET_Release(piKey);
            piKey = NULL;
         }
 
      }
   } else {
      RootForm_Update(me, FORMITEM_THEME_BASENAME, IROOTFORM_GetTopForm(po));
   }
 
   return AEE_SUCCESS;
}
 
 
void RootForm_GetClientRect(IRootForm *po, IXYContainer **ppo, AEERect *rc)
{
   DECL(RootForm);
 
   if (rc) {
      *rc = me->rcClient;
   }
 
   if (ppo && me->piContainer) {
      *ppo = IROOTCONTAINER_TO_IXYCONTAINER(me->piContainer);
      IROOTCONTAINER_AddRef(me->piContainer);
   }
}
 
IForm *RootForm_GetForm(IRootForm *po, IForm *pifRef, boolean bNext, boolean bWrap)
{
   DECL(RootForm);
   IForm *piForm = 0;
   int nrForms, formIndex;
   
   if (me->piForms == NULL)
      return NULL;
 
   nrForms = IVECTORMODEL_Size(me->piForms);
 
   if (pifRef == NULL) {
      formIndex = bNext ? 0 : nrForms - 1;
      IVECTORMODEL_GetAt(me->piForms, formIndex, (void **)&piForm);
      return piForm;
   }
 
   formIndex = RootForm_GetFormIndex(me, &pifRef);
 
   if (formIndex < 0)
      return NULL;
 
   formIndex += bNext ? 1 : -1;
   if (formIndex < 0) {
      formIndex = bWrap ? nrForms - 1 : -1;
   } else if (formIndex >= nrForms) {
      formIndex = bWrap ? 0 : - 1;
   }
   
   if (formIndex < 0)
      return NULL;
 
   IVECTORMODEL_GetAt(me->piForms, formIndex, (void **)&piForm);
   return piForm;
}
 
int RootForm_ResolveForm(IRootForm *po, char const *szFormUrl, IForm **ppiForm)
{
   DECL(RootForm);
   IWebUtil *piWebUtil = 0;
   AEECLSID formClsId;
   int result;
   UrlParts parts;
   char *path = 0;
 
   if (!ppiForm || !szFormUrl)
      return EBADPARM;
 
   // Assume failure
   *ppiForm = 0;
 
   // Parse the URL
   result = ISHELL_CreateInstance(FORM_SHELL(me), AEECLSID_WEBUTIL, (void **) &piWebUtil);
 
   if (result == 0) 
      result = IWEBUTIL_ParseUrl(piWebUtil, szFormUrl, &parts);
 
      // Check the scheme
   if (result == 0
       && (!UP_HASSCHM(&parts) || STRNCMP(parts.cpcSchm,FORM_URL_SCHEME,sizeof(FORM_URL_SCHEME)-1)))
       result = ESCHEMENOTSUPPORTED;
 
      // Do we have a path?
   if (result == 0
       && (!UP_HASPATH(&parts) || UP_PATHLEN(&parts) <= 0))
      result = ESCHEMENOTSUPPORTED;
 
   // Extract the path (we need it to be NULL terminated)
   if (result == 0 
       && 0 == (path = MALLOC(UP_PATHLEN(&parts)+1)))
      result = ENOMEMORY;
 
   if (result == 0) {
      STRNCPY(path, parts.cpcHost, UP_PATHLEN(&parts)+1);
 
      // Does a handler exist for this path, of type AEEIID_FORM?
      if (0 == (formClsId = ISHELL_GetHandler(FORM_SHELL(me), AEEIID_FORM, path)))
         // Nope...
         result = ESCHEMENOTSUPPORTED;
   }
 
   if (result == 0)
      // Got the actual class id, lets create the form
      result = ISHELL_CreateInstance(FORM_SHELL(me), formClsId, (void **) ppiForm);
 
   //
   // TODO: We could use IWEBUTIL_ParseFormFields() to parse parts.cpcSrch 
   //       for known Form properties and apply them here...
 
   RELEASEIF(piWebUtil);
   FREEIF(path);
 
   return result;
}
 
void RootForm_Dtor(RootForm *me)
{
   IROOTFORM_RemoveForm(ROOTFORM_TO_IROOTFORM(me), FORM_ALL);
 
   RELEASEIF(me->piTitle);
   RELEASEIF(me->piSoftkeys);
   RELEASEIF(me->piContainer);
   RELEASEIF(me->piBackground);
   RELEASEIF(me->titleInfo.piImage);
   RELEASEIF(me->piForms);
   RELEASEIF(me->piActiveWidget);
   RELEASEIF(me->piThemeFile);
   FREEIF(me->themeFile);
 
   Form_Dtor(&me->base);  
}
 
uint32 RootForm_Release(IRootForm *po)
{
   DECL(RootForm);
   
   if (FORM_NREFS(me) == 1)
      RootForm_Dtor(me);
 
   return Form_Release(IROOTFORM_TO_IFORM(po));
}
 
int RootForm_QueryInterface(IRootForm *po, AEECLSID clsid, void **ppo)
{
   if (clsid == AEEIID_ROOTFORM) {
      *ppo = po;
      Form_AddRef(IROOTFORM_TO_IFORM(po));
      return AEE_SUCCESS;
   }
 
   return Form_QueryInterface(IROOTFORM_TO_IFORM(po), clsid, ppo);
}
 
int RootForm_Construct(RootForm *me, AEEVTBL(IRootForm) *pvt, IModule *piModule, IShell *piShell)
{
   int result;
   WExtent extent;
   WidgetPos pos;
   IDisplay *piDisplay = 0;
   ICanvas *piCanvas = 0;
 
   Form_Ctor(&me->base, (AEEVTBL(IForm) *)pvt, piModule, piShell, 
             (PFNHANDLER)RootForm_HandleEvent);
 
   pos.x = 0;
   pos.y = 0;
   pos.bVisible = TRUE;
   SETWEXTENT(&extent, 0, 0);
 
   // Form overrides
   pvt->Release         = RootForm_Release;
   pvt->QueryInterface  = RootForm_QueryInterface;
   // RootForm definitions
   pvt->InsertForm      = RootForm_InsertForm;
   pvt->RemoveForm      = RootForm_RemoveForm;
   pvt->GetClientRect   = RootForm_GetClientRect;
   pvt->GetForm         = RootForm_GetForm;
   pvt->ResolveForm     = RootForm_ResolveForm;
 
   result = ISHELL_CreateInstance(piShell, AEECLSID_VECTORMODEL, (void **)&me->piForms);
 
   if (result == 0) {
      IVECTORMODEL_SetPfnFree(me->piForms, (PFNNOTIFY)RootForm_FreeFormEntry);
 
      result = ISHELL_CreateInstance(piShell, AEECLSID_DISPLAY, (void **)&piDisplay);
   }
 
   if (result == 0)
      result = ISHELL_CreateInstance(piShell, AEECLSID_ROOTCONTAINER, (void **)&me->piContainer);
 
   if (result == 0)
      result = IROOTCONTAINER_QueryInterface(me->piContainer, AEEIID_WIDGET, (void **)&me->base.piWidget);
 
   if (result == 0)
      result = ISHELL_CreateInstance(piShell, AEECLSID_RESFILE, (void **)&me->piThemeFile);
 
   if (result == 0)
      result = ISHELL_CreateInstance(piShell, AEECLSID_IMAGEWIDGET, (void **)&me->piBackground);
 
   if (result == 0) {
      IWIDGET_SetFlags(me->piBackground, IDF_ALIGN_RIGHT | IDF_ALIGN_BOTTOM);
 
      // Insert, extent will be fixed up in SetDisplay below
      result = IROOTCONTAINER_Insert(me->piContainer, me->piBackground, WIDGET_ZBOTTOMMOST, &pos);
   }
 
   if (result == 0)
      // Construct title
      result = ISHELL_CreateInstance(piShell, AEECLSID_IMAGESTATICWIDGET, (void **)&me->piTitle);
 
   if (result == 0) {
      extent.height = 15;
      // Set title font to bold by default.  Apps and themes can override it.
      IWIDGET_SetFontClass(me->piTitle, AEECLSID_FONTSYSBOLD);
 
      IWIDGET_SetShadowOffsetY(me->piTitle, 0);
      IWIDGET_SetBorderWidth(me->piTitle, 0);
      IWIDGET_SetExtent(me->piTitle, &extent);
      // Add to container
      result = IROOTCONTAINER_Insert(me->piContainer, me->piTitle, WIDGET_ZTOPMOST, &pos);
   }
 
   if (result == 0)
      // Construct Softkeys
      result = ISHELL_CreateInstance(piShell, AEECLSID_SOFTKEYWIDGET, (void **)&me->piSoftkeys);
 
   if (result == 0) {
      IWIDGET_SetShadowOffsetY(me->piSoftkeys, -1);
      IWIDGET_SetBorderWidth(me->piSoftkeys, 0);
      IWIDGET_SetExtent(me->piSoftkeys, &extent);
      IWIDGET_SetLeftPadding(me->piSoftkeys, 2);
      IWIDGET_SetRightPadding(me->piSoftkeys, 2);
 
      // Insert at 0, 0. Correct positioning will happen in SetDisplay
      result = IROOTCONTAINER_Insert(me->piContainer, me->piSoftkeys, WIDGET_ZTOPMOST, &pos);
   }
 
   if (result == 0)
      result = RootForm_SetDisplay(me, piDisplay);
 
   if (result == 0) {   
      char* pTheme = 0;
      IFORM_SetThemeBaseName(ROOTFORM_TO_IFORM(me), "Root");
 
      IFORM_GetThemeBaseName(ROOTFORM_TO_IFORM(me), &pTheme);
      pTheme = (pTheme) ? pTheme : "(None)";
 
      BUIT_LOG("FORMS EVT: Construct Set Theme Started for %s", pTheme);
 
      IROOTFORM_SetThemeFileName(ROOTFORM_TO_IROOTFORM(me), "theme.bar");
 
      BUIT_LOG("FORMS EVT: Construct Set Theme Finished for %s", pTheme);
 
   } else {
      RootForm_Dtor(me);
   }
 
   RELEASEIF(piDisplay);
   RELEASEIF(piCanvas);
   
   return result;
}
 
 
int RootForm_New(IRootForm **ppo, IModule *piModule, IShell *piShell)
{
   RootForm *me = MALLOCREC_VTBL(RootForm, IRootForm);
   int result;
 
   *ppo = (IRootForm *)me;
 
   if (!me)
      return ENOMEMORY;
 
   result = RootForm_Construct(me, GETVTBL(me, IRootForm), piModule, piShell);
   
   if (result != 0) {
      *ppo = NULL;
      FREE(me);
   }
   
   return result;
}
 
 

八、小结

  • 注释应该准确易懂,防止二义性,错误的注释有害无利
  • 注释是对代码的提示,避免臃肿和喧宾夺主
  • 一目了然的代码避免加注释
  • 不要用缩写来注释代码,这样可能会产生误解
  • 注释用于阐述原因和意图而不是描述程序的运行过程

到此这篇关于C语言详细讲解注释符号的使用的文章就介绍到这了,更多相关C语言 注释符号内容请搜索好代码网以前的文章或继续浏览下面的相关文章希望大家以后多多支持好代码网!

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