Pydm

======================
Hello again, PyDM users! Version 1.2 is now available. This release is focused mostly on bug fixes, and the addition of many, many unit tests. We do have a few user-facing improvements, though.

New Features
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* Major improvements to the Scale Widget (Thanks laispc)
* More customizability of PyDMImageView in Designer.

Full List of Changes
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* Changed the default EPICS plugin to PyEPICS, rather than pyca.
* Major improvements to the Scale Widget (Thanks laispc)
* Expanded documentation for Tab Bar Widget
* Reorganized documentation for PyDM developers
* Many warning messages have been migrated from print statements to use the python logger system.
* Fix bugs in the right-click context menu for widgets.
* Unit tests and documentation added for PyDM utility classes.
* PyDM now has CI for Windows builds as well, through AppVeyor.
* PyDM will now display a blank main window if launched without a filename, rather than silently running with no UI at all.
* Unit tests added for PyDMPushButton.
* Add a command line option to the PyDM executable to use PyDM without showing a main window, for users who want to subclass PyDMApplication.
* Fix a bug where the PyDMPushButton would never send its value on push if the configured value was '0'.
* More customizability of PyDMImageView in Designer.
* PyDMImageView no longer has a hard-coded maximum value for the image data.
* Unit tests for PyDMLineEdit.
* Unit tests for PyDM Widget base classes.
* Fix a bug on PyDMBitIndicator which was causing crashes.
* Unit tests for PyDMShellCommand.
* Fix a bug when reshaping image data with C-like ordering in PyDMImageView.
* Unit tests for PyDMFrame.
* Unit tests for PyDMSpinbox.
* Fix crashes in PyDMDrawingImage when an invalid image file path was specified.
* PyDMEnumComboBox now inherits from QComboBox instead of QFrame. The API for this widget is still the same, but now all the QComboBox methods can be easily overridden.
* Fix an issue where changing a widget's `channel` property wouldn't update its internal variable.
* Fix a bug when dynamically adding curves to PyDMTimePlots.
* Fixed a crash when a zero-length waveform was used by a PyDMWaveformPlot.
* Refactored the data plugin loading system.
* Add a PyDMLogWidget to display logging information.
* Update the year on PyDM's license document.
* Add a new widget category for 'container' widgets like PyDMTabBar and PyDMFrame.
* Unit tests for PyDMEnumComboBox.
* Fix a crash when trying to load a new tool on a blank PyDMMainWindow.
* PyDMLabels now treat character waveforms as null-terminated.
* Fix a crash when trying to open a non-existent file in a new window with a PyDMRelatedDisplay button.
* Fix a crash case where PyDM sometimes tried to disconnect from the same channel multiple times.
* Fix a crash when a PyDM widget had a blank `channel` property.

This is a pretty small release in terms of changes, but its got an important bug fix to PyDMImageViews, so we wanted to get it out quickly.

New Features
* Data plugins can now be dynamically loaded from a user-specified directory outside of where PyDM is installed. Simply set an environment variable named 'PYDM_DATA_PLUGINS_PATH' which points to the directory you want to load from.
* The PyDMShellCommand and PyDMRelatedDisplay button widgets now have a boolean property to hide/show their default icons.

Bug Fixes
* Fixed a bug in ImageView that prevented its channels from ever connecting. (Thanks hhslepicka)
* Fixed a race condition in the PyEPICS plugin that would sometimes prevent it from working (Thanks ZLLentz)

Version 1.0, just in time for the end of the year! At this point, we think that PyDM is ready for general use. In the spirit of semantic versioning, we’re promising that from this point forward, all 1.x releases will not change the public interfaces for widgets (both in Python and Designer), data plugins, and the application. That isn’t to say we don’t have more new features to come in 1.x releases, just that you’ll hopefully not have to worry about your displays breaking with updates.

The star of this release is the new ‘external tool interface’. This system lets you write simple interfaces to launch external applications (for example, a strip-tool, or archive viewer). Each external tool gets a menu item in the new ‘Tools’ menu, as well as in a menu that appears when right-clicking on widgets. When you execute an external tool, it is passed a list of all channels in the current widget, as well as the widget instance itself. This lets you do some clever stuff: launch a history plot for the PV in a widget! Open a browser window and start writing a logbook entry, with a list of PVs attached! Because we don’t know what external tools you are using, PyDM itself will only come with a couple examples. We’re excited to see what people come up with.

Finally, we’ve got all of the usual goodies below: One breaking change to pydm-testing-ioc, a few new smaller features, and several bug fixes.

Thanks for using PyDM! <3

Breaking Changes
* pydm-testing-ioc was moved from the `scripts` folder to the new location `examples/testing_ioc` with the `access_rules.as` file. (Thanks hhslepicka)
* The ‘pydm’ launcher is now autogenerated at the proper location on the system through the package installation procedure. This means that the scripts and data folders are gone. (Thanks hhslepicka)
* PyDMIndicator is now deprecated after warning on previous versions of PyDM. Please use PyDMDrawingRectangle as a replacement.

New Features
* Added a pyqtProperty to ImageView that lets you specify a color map in Designer.
* Expanded documentation with some extra steps explaining how to build the PyDM prerequisites.
* Add a ‘read-only mode’ to PyDM. At the command line, you can specify a ‘--read-only’ argument, which prevents the user from writing to any channels. (Thanks hhslepicka)
* Add a new ‘Show connections…’ menu option, which opens a window with a list of all channels used on the current display. The protocol for each channel and the connection status are also displayed. The list of channels can be dumped to a text file (one channel per line).
* Add context menu to PyDMRelatedDisplay to open in a new Window.
* About Screen with useful information of Python Modules, External Tools and Data Plugins in use.

Bug Fixes
* Fixed the tag_prefix at setup.cfg so the version is represented correctly and not with the “v” from the tag name. (Thanks hhslepicka)
* Changed .gitattributes in order to make the “Pickle” files behave as binary files and not having its line endings (LF) changed to CRLF on checkout and break the code. Issue 196. (Thanks hhslepicka)
* Fixed the open_file behaviour under Windows. Issues 32 and 196. (Thanks hhslepicka)
* Fixed PyDM launcher generation and install (`pydm` for Linux and OSX and `pydm.exe` for Windows) (Thanks hhslepicka)
* Prevent GUI from crashing if an exception is raised when executing a shell command (Thanks ZLLentz)
* Fixed a crash if PyDMImageView receives a (0,0) image.
* Fixed the camviewer to work with the new colormaps file and the enhanced version of the ImageView. Issue 210. (Thanks hhslepicka)

Like all of the releases so far, 0.4.0 fixes a bunch of bugs, and adds a few new features. The biggest thing to note is that PyQt4 is no longer supported - from this release onward, PyDM only supports PyQt5. There are major breaking changes too, that may require you to modify .ui or .py display files. This is probably the last minor release before we finally increment the major version number. Once we hit 1.0, the APIs for the widgets 'fixed', and .ui/.py display files you create for 1.0 should continue to work without modification in any 1.x release. We will continue adding additional features in 1.x releases, but will not make any breaking changes.

Breaking Changes
* PyQt4 is no longer supported, due to changes that require PyQt5 features.
* All PyDM widgets now inherit from a base 'PyDMWidget' class. Widgets that write to PVs are derived from a subclass of PyDMWidget called PyDMWritableWidget. These base classes provide good default behavior for handing read/write access changes, connection status changes, and alarm changes, which makes developing new widgets (and maintaining old ones) much easier.
* PyDMRelatedDisplayButton is no longer alarm sensitive, and now inherits from QPushButton instead of QFrame. This is only a breaking change if you've been using PyDM in between 0.3 and 0.4. It is recommended to embed a related display button within the new PyDMFrame if you want an alarm-sensitive border around your button.

The last two changes will cause a warning messages when you open old .ui files in Qt Designer. Simply opening the file and saving it should prevent the warning from appearing in the future, and even without saving, these .ui files should still work in PyDM. Python-based displays which relied on old behavior might crash unless they are modified.

New Features
* PyDM widgets are now grouped into different categories in Qt Designer, which makes them much easier to find. (Thanks laispc)
* PyDM plot classes now have Qt properties for specifying manual plot ranges in code and in Qt Designer.
* The navigation bar (forward/back/home buttons) has been totally redone, and can be shown/hidden via menu actions and command line arguments.
* A third plot type has been added: PyDMScatterPlot. Scatter plots take two scalar channels, and plot one channel vs. the other on an X vs Y plot. A configurable number of prior data points are displayed on the plot. Multiple curves are possible, with different colors and data symbols.
* Documentation has been significantly improved: All widgets are now documented (useful for folks developing python-based displays), the PyDMApplication class is documented, documentation has been added on how to create python-based displays, and there is a new guide to getting started with PyDM.
* The documentation is generated any time new code is committed, and the most up-to-date version is available at http://slaclab.github.io/pydm/ (Thanks hhslepicka)
* Waveform plots now have options to redraw only when one of the two axes update, or only after both have updated, in addition to the previous behavior of redrawing when either axes updated.
* The Archiver Appliance data plugin (which is really just a proof of concept right now) has been modified to use an environment variable to specify the URL of the archiver instance, rather than hard-coded in the plugin itself (Thanks hhslepicka)
* PyDM plots now have many more options for curves (line width, line type, etc.) (Thanks fernandohds564)
* The 'units' module in the utilities has been improved with even more unit types. (Thanks fernandohds564)
* PyDMSpinBox's step size picker can now be shown an hidden at runtime via a right-click menu option. (Thanks fernandohds564)
* A new PyDMScaleIndicator widget provides a bar-graph-like indicator for a single scalar value. The widget has a configurable scale tick marks, and works in both horizontal and vertical orientations. (Thanks laispc)
* PyDMWaveformTable can now edit waveform data as well as read it. It can also transform one-dimensional arrays into two-dimensions. Labels can be added to both rows and columns.
* All plot-related classes now inherit from common plot base classes, making maintenance much easier (Thanks fernandohds564)
* Widgets can now be imported directly from pydm.widgets, no need to import from the individual widget's module anymore. For example `from pydm.widgets.line_edit import PyDMLineEdit` can now be `from pydm.widgets import PyDMLineEdit`. (Thanks hhslepicka)
* PyDM now has an Anaconda recipe! See the documentation for more details. (Thanks hhslepicka)
* The image widget and plot widgets all handle updates differently now - they have a fixed maximum update rate that is user-configurable. This prevents massive, extremely-fast updating waveforms from bringing the whole display to a grinding halt.
* A new PyDMFrame widget now provides a general-purpose way to give any widget (even a non-PyDM widget!) an alarm sensitive border. This also allows you to show one alarm border for a group of multiple widgets, or use a different PV for the alarm than the PV used for the control widget. (Thanks hhslepicka)
* The menu bar at the top of the window and the status bar at the bottom of the window are now toggle-able via menu actions, keyboard shortcuts, and command line arguments. (Thanks hhslepicka)
* PyDMDrawingImage now has an initializer argument to specify an image file at initialization time.
* The Edit in Designer menu item can now be used to open python-based displays (or displays that use both .ui files and .py files) too. The .py file will be opened in the default text editor for your OS. (Thanks hhslepicka)
* An option has been added to PyDMShellCommand buttons to allow them to run the command multiple times, even before the initial command is finished running. This is useful when the button is used to launch a long-lived process, like an application. (Thanks hhslepicka)

Bug Fixes
* Warnings about "TypeError" no longer appear when manipulating PyDMSliders in Qt Designer.
* Fix problems with unit strings disappearing if labels were configured with precision of 0. (Thanks laispc)
* Fixed a crash when using PyDMWaveformTable. (Thanks hhslepicka)
* Better error handling for PyDMTimePlots and PyDMWaveformPlots curve properties in Qt Designer. (Thanks gabrielfedel)
* Fix broken 'camviewer' example (Thanks hhslepicka)
* Widgets that never established a connection to a channel are now properly disabled.
* Fix string encoding problems in the PyEPICS plugin (Thanks ZLLentz)
* Fix an edge-case where a not-fully-connected PV may try to send a connection state change, causing a crash (Thanks ZLLentz)
* Fix issues with PyDMSpinBox when used in locales which use commas as decimal separators rather. (Thanks fernandohds564)
* Fix a bug when adding many Y signals to a PyDMTimePlot via the widget's initializer. (Thanks fernandohds564)
* Fix bug where values equal to 0 would never cause PyDMEnumComboBox to update (Thanks gu1lhermelp)
* Fix bug where PyDMPushButton would not send values equal to 0 (Thanks fernandohds564)
* Fix bugs related to alarm borders (Thanks xresende)
* Better clean-up of signals/slots when disconnecting from a channel (Thanks ZLLentz)
* PyDM displays now resize in a less-braindead way that obeys the size of the .ui file, and no longer attempts to make the window as small as possible.
* PyDMDrawingImages now properly show images in Qt Designer, even when the images are specified via relative paths (Thanks hhslepicka)
* Drawing widgets now have size hints to prevent layouts from crushing them into oblivion.

PyDM v0.3 adds new widgets, new features, and many bug fixes. Please note the breaking changes section below - if you use plot widgets, some action will need to be taken to make your displays work again. As a reminder, the project uses semantic versioning, and as we are still in major version 0, any release may have breaking changes, although we try to keep them to a minimum.

Breaking Changes
- PyDMTimePlot and PyDMWaveformPlot now accept multiple curves for each plot. To edit the curves for a plot in designer, right click it and choose 'edit curves', or double click on the widget. This will bring up a curve editor where the channel, label, and color for each curve can be configured. Please note that existing plots will no longer function, plots in .ui files and plots created in .py files need to be updated to use the new properties provided by the widgets. (thanks laispc)

New Features
- The macro system has been extended to python based displays as well. Any Display subclass should expect to receive a 'macros' keyword argument in the initalizer, which is a dictionary with macro values, keyed on macro names.
- In the 'View' menu there is now an option to show the path to the file you are currently viewing, rather than its title.
- A new SpinBox widget to manipulate float values has been added (thanks mennodoor)
- Display subclasses no longer need to define an 'intelclass' variable, PyDM will inspect the loaded python file and find the appropriate class to use.
- The 'File' menu now has an 'Open...' item which brings up a file dialog box to pick a file to load. (thanks hhslepicka)
- A set of widgets for drawing shapes and static images have been added. These widgets all have alarm sensitivity in fill color and border. (thanks hhslepicka)
- A widget called PyDMByteIndicator has been added for viewing the individual bits in a status 'byte'. Each bit has a configurable label, and the endianness of the byte, and number of bits contained within, are configurable.
- A widget called PyDMSymbol has been added. The symbol widget takes a enum channel as an input, and displays a different image for each state of the enum. Most common image file types are supported, as well as SVG (scalable vector graphics) files.
- PyDM now supports an environment variable to set a default protocol. If you set the PYDM_DEFAULT_PROTOCOL environment variable to a protocol specifier (for example, 'ca' for EPICS), you can define channels throughout PyDM without supplying the 'ca://' before the rest of the address.
- PyDMRelatedDisplayButtons now have an option to open their file in a new window, rather than in the existing window. (Note from Matt: Please use this feature sparingly to avoid a huge number of windows that operators need to clean up!)
- Data plugins can now be added by adding a file in pydm/data_plugins/. It is no longer necessary to modify the PyDMApplication to register a new plugin.
- PyDMPushButtons now have an option to display a confirmation dialog box before sending the value to the PV. Additionally, an 'enter password' box option has been added (thanks hhslepicka).
- Data plugins can now send control limits and units to widgets. These can be used for example to set the maximum and minimum values the widget can handle. Support for control limits and units has been added to existing widgets, where applicable. These properties can be overridden by the display author if desired.

Bug Fixes
- Many problems with PyQt5 compatibility were fixed (thanks gabrielfedel and laispc)
- Handle cases where EPICS PVs return bytestrings for units in Python 3 (thanks gabrielfedel)
- Widgets can implement slots for only one signal type (float, int, or string), they will not fail if all types are not implemented.
- Fix a crash when using PyEPICS plugin, and a PV info field (units, precision, etc.) changes without the value changing.
- Add handling of EPICS long, char, and short data types to EPICS plugins (thanks Tim Madden (argonnexraydetector))
- Clicking on related display buttons without a defined filename property no longer crashes PyDM.
- Image color maps scaling calculations no longer rely on 8-bit image values (thanks mennodoor)
- Fix a bug with PyDMLabel and PyDMSlider where they would not visually show disconnected status when their channel disconnects (thanks laispc)
- Fixed a bug that prevented tooltips from displaying when middle clicking widgets. Also fixes problems when copying channel information to the clipboard when a widget is middle clicked. (thanks scalverson)
- Fix a bug where old widgets were left in an embedded display after the file displayed was changed. (thanks hhslepicka)
- Fix a bug where data plugins would sometimes get passed channels with empty 'address' fields and crash.
- Fix a bug where the slider widget would crash if it was sent an int value instead of a float. (thanks mennodoor)
- Whitespace has been standardized throughout the project to four spaces per tab. (thanks hhslepicka)