Developers 

Just a quicky: I wrote a little plugin for KTextEditor which supplies you with basic error checking when you save documents. Currently only PHP (via php <span class="re5">-l</span>) and JavaScript (via JavaScript Lint) are supported. Screenshots PHP error list of errors Requirements usual tools for compiling C++, e.g. gcc. cmake Qt development packages, i.e. under Ubuntu: <span class="kw2">sudo</span> <span class="kw2">aptitude</span> <span class="kw2">install</span> libqt4-dev KDE 4.2 with development packages for kdelibs and kdebase, i. Read More

The Kate Editor Component (also called KatePart) has its own undo/redo system. It did not change much since KDE2 and basically it is very simple. Meanwhile there are classes for undo/redo support in Qt as well. In fact both systems are very similar. This article focuses on Kate Part’s system. Text Operations First we have to take a look at what actions need to be saved. In Kate Part this basically comes down to Read More

As food for thought and in reply to Why Encapsulation is a Good Thing it’s interesting to take a closer look. What does encapsulation mean exactly, and what can you do with it? Maybe what you really want is Information Hiding? …and encapsulation is just a way of possibly achieving it? If you are interested in the details/differences, read the article Encapsulation is not Information Hiding.

There was some confusion with regard to my last blog about leaking memory. Suppose the ui_mywidget.h files looks like this: class Ui_Widget { public: QGridLayout *gridLayout; QGroupBox *groupBox; QGridLayout *gridLayout1; QListWidget *listWidget; QSpacerItem *spacerItem; QPushButton *pushButton; void setupUi(QWidget *Widget); void retranslateUi(QWidget Widget); }; Of course, those 6 QObject derived classes are deleted. But the sizeof(Ui_Widget) = 6 * sizeof(void) = 24 bytes are not deleted. As Ui_Widget is not QObject derived those 24 bytes leak. Read More

The KDE codebase often uses a forward declaration in the .h-file to speedup compilation. The code often looks like this: // header file namespace Ui { class MyWidget; } class MyDialog : public KDialog { // ... private: Ui::MyWidget *ui; }; The impl looks like this: // source file #include "mydialog.h" #include "ui_mywidget.h" MyDialog::MyDialog() : KDialog() { QWidget *w = new QWidget(this); setMainWidget(w); ui = new Ui::MyWidget(); // allocation ui->setupUi(w); // ui->. Read More

Kate Part in KDE4 supports the ECMAScript (JavaScript) language by using kjs. In KDE3 we had several hard-coded indenters in C++, the idea is to let scripts do all the indentation in KDE4. How does it work? It is similar to vim: You simply create a script in the directory $KDEDIR/share/apps/katepart/jscript. An indentation script has to follow several rules: it must have a valid script header (the first line must include the string kate-script and indentation scripts must have the type: indentation) it must define some variables and functions Whenever the user types a character, the flow in Kate Part works like this Read More

Warning This is an outdated tutorial and is only kept here for historical reasons. For an up-to-date version of the tutorial please check https://develop.kde.org/docs/apps/kate/plugin/ Introduction First at all, why writing plugins for an editor ? Good question, and I hope I have a good answer: Because we want Kate to be small and all extended features not all users need should go into plugins (like CVS suppport, project managment, coffee cooking ;) Therefore Kate provides a quite full-featured plugin interface and interfaces to all important stuff in the Kate application (the documents, views, windows, sidebar …). Read More