Archive:Development/Tutorials/KCmdLineArgs (zh TW)

摘要

現在我們有了一個可以載入和儲存檔案的文字編輯器。我們要讓這個編輯器像其他桌面程式一樣，能用命令列參數開啟檔案，甚至可以在 Dolphin 裡使用開啟方式來開啟檔案。

程式碼

main.cpp

<syntaxhighlight lang="cpp-qt" line>

1. include <KApplication>
2. include <KAboutData>
3. include <KCmdLineArgs>
4. include <KUrl> //new

1. include "mainwindow.h"

int main (int argc, char *argv[]) {

 KAboutData aboutData( "tutorial5", "tutorial5",
     ki18n("Tutorial 5"), "1.0",
     ki18n("A simple text area which can load and save."),
     KAboutData::License_GPL,
     ki18n("Copyright (c) 2007 Developer") );
 KCmdLineArgs::init( argc, argv, &aboutData );

 KCmdLineOptions options; //新增的
 options.add("+[file]", ki18n("Document to open")); //新增的
 KCmdLineArgs::addCmdLineOptions(options); //新增的

 KApplication app;

 MainWindow* window = new MainWindow();
 window->show();

 KCmdLineArgs *args = KCmdLineArgs::parsedArgs(); //新增的
 if(args->count()) //新增的
 {
   window->openFile(args->url(0).url()); //新增的
 }

 return app.exec();

}

mainwindow.h

<syntaxhighlight lang="cpp-qt" line>

1. ifndef MAINWINDOW_H
2. define MAINWINDOW_H

1. include <KXmlGuiWindow>
2. include <KTextEdit>

class MainWindow : public KXmlGuiWindow {

 Q_OBJECT
 
 public:
   MainWindow(QWidget *parent=0);
   void openFile(const QString &inputFileName); //新增的
 
 private:
   KTextEdit* textArea;
   void setupActions();
   QString fileName;

 private slots:
   void newFile();
   void openFile();
   void saveFile();
   void saveFileAs();
   void saveFileAs(const QString &outputFileName);

};

1. endif

mainwindow.cpp

<syntaxhighlight lang="cpp-qt" line>

1. include "mainwindow.h"

1. include <KApplication>
2. include <KAction>
3. include <KLocale>
4. include <KActionCollection>
5. include <KStandardAction>
6. include <KFileDialog>
7. include <KMessageBox>
8. include <KIO/NetAccess>
9. include <KSaveFile>
10. include <QTextStream>

MainWindow::MainWindow(QWidget *parent)

   : KXmlGuiWindow(parent),
     fileName(QString())

{

 textArea = new KTextEdit;
 setCentralWidget(textArea);

 setupActions();

}

void MainWindow::setupActions() {

 KAction* clearAction = new KAction(this);
 clearAction->setText(i18n("Clear"));
 clearAction->setIcon(KIcon("document-new"));
 clearAction->setShortcut(Qt::CTRL + Qt::Key_W);
 actionCollection()->addAction("clear", clearAction);
 connect(clearAction, SIGNAL(triggered(bool)),
         textArea, SLOT(clear()));

 KStandardAction::quit(kapp, SLOT(quit()),
                       actionCollection());

 KStandardAction::open(this, SLOT(openFile()),
                       actionCollection());

 KStandardAction::save(this, SLOT(saveFile()),
                       actionCollection());

 KStandardAction::saveAs(this, SLOT(saveFileAs()),
                       actionCollection());

 KStandardAction::openNew(this, SLOT(newFile()),
                       actionCollection());

 setupGUI();

}

void MainWindow::newFile() {

 fileName.clear();
 textArea->clear();

}

void MainWindow::saveFileAs(const QString &outputFileName) {

 KSaveFile file(outputFileName);
 file.open();
 
 QByteArray outputByteArray;
 outputByteArray.append(textArea->toPlainText());
 file.write(outputByteArray);
 file.finalize();
 file.close();
 
 fileName = outputFileName;

}

void MainWindow::saveFileAs() {

 saveFileAs(KFileDialog::getSaveFileName());

}

void MainWindow::saveFile() {

 if(!fileName.isEmpty())
 {
   saveFileAs(fileName);
 }
 else
 {
   saveFileAs();
 }

}

void MainWindow::openFile() //變更 {

 openFile(KFileDialog::getOpenFileName());

}

void MainWindow::openFile(const QString &inputFileName) //新增的 {

 QString tmpFile;
 if(KIO::NetAccess::download(inputFileName, tmpFile, 
        this))
 {
   QFile file(tmpFile);
   file.open(QIODevice::ReadOnly);
   textArea->setPlainText(QTextStream(&file).readAll());
   fileName = inputFileName;

   KIO::NetAccess::removeTempFile(tmpFile);
 }
 else
 {
   KMessageBox::error(this, 
       KIO::NetAccess::lastErrorString());
 }

}

tutorial5ui.rc

<?xml version="1.0" encoding="UTF-8"?> <gui name="tutorial5"

    version="1"
    xmlns="http://www.kde.org/standards/kxmlgui/1.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.kde.org/standards/kxmlgui/1.0
                        http://www.kde.org/standards/kxmlgui/1.0/kxmlgui.xsd" >

 <MenuBar>
   <Menu name="file" >
     <Action name="clear" />
   </Menu>
 </MenuBar>

 <ToolBar name="mainToolBar" >
   <text>Main Toolbar</text>
   <Action name="clear" />
 </ToolBar>

</gui> 這和前兩個教學的 tutorialxui.rc 一樣，唯一的改變就是從 tutorialx 變成了tutorial5。

解釋

mainwindow.h

這裡我們只新增 openFile 函式，它接受一個 QString 作為參數。 <syntaxhighlight lang="cpp-qt"> void openFile(const QString &inputFileName);

mainwindow.cpp

這部分沒有新增程式碼，只是重新整理一下而已。所有 void openFile() 裡的東西都被移到了 void openFile(const QString &inputFileName) 裡，除了 KFileDialog::getOpenFileName() 的呼叫。

這樣，如果我們要一個對話框就呼叫 openFile()，如果已經有檔案名稱，呼叫openFile(QString) 就可以了。

main.cpp

This is where all the KCmdLineArgs magic happens.

編譯、安裝與執行

CMakeLists.txt

project(tutorial5)

find_package(KDE4 REQUIRED) include_directories( ${KDE4_INCLUDES} )

set(tutorial5_SRCS

 main.cpp
 mainwindow.cpp

)

kde4_add_executable(tutorial5 ${tutorial5_SRCS})

target_link_libraries(tutorial5 ${KDE4_KDEUI_LIBS}

                               ${KDE4_KIO_LIBS})

install(TARGETS tutorial5 DESTINATION ${BIN_INSTALL_DIR}) install( FILES tutorial5ui.rc

        DESTINATION  ${DATA_INSTALL_DIR}/tutorial5 )

有了這個檔案，這個教學就可以像教學3和4一樣建構和執行了。更多資訊，請見教學3。

mkdir build && cd build
cmake .. -DCMAKE_INSTALL_PREFIX=$HOME
make install
$HOME/bin/tutorial5

繼續前進

現在你可以開始學習下一課：### (TODO User:milliams) 教學。