LatteDock

    From KDE TechBase
    Revision as of 11:03, 13 July 2019 by Magentium (talk | contribs) (Version 0.3 of the page completed)
    The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

    Technical Details

    This is an effort to expose some of the Latte Tricks and APIs that developers can use in order to leverage Latte Dock capabilities. Two major sections are currently provided, Applets and Indicators. In the Applets section you will understand how a Plasma QML applet can obtain information from Latte and how it can be implemented properly in order to work just fine with parabolic effect. In Indicators section you will learn how you can create your own Latte Indicators. NOTE: All APIs are provided since Latte [v0.9.0] and if a new property or function is added then in that case there will be a tag mentioning when it was introduced for example [v0.9.4]

    Applets

    Can a Plasma Applet access Latte Information?

    Most definitely! This is very simple. The only thing you need to add in your applet main QML file is:

    import QtQuick 2.0
    
    Item {
        id: root
    
        //! Latte Connection
        property QtObject LatteBridge: null
        //!
    }
    

    The LatteBridge object is assigned from Latte when applet is loaded and it is the “ONE to rule them ALL” way to communicate with Latte. Important thing to mention is that if your applet is using both Compact and FullRepresentation(s) then the relevant code should be placed in CompactRepresentation.

    import QtQuick 2.0
    
    Item {
        id: root
    
        Plasmoid.compactRepresentation: Item {
            //! Latte Connection
            property QtObject LatteBridge: null
            //!
        }
    }
    


    After adding LatteBridge property it is straightforward to identify when your applet is inside a Latte panel/dock OR in a Plasma panel with:

    readonly property bool inLatte: LatteBridge !== null


    Can a plasma applet behave properly with parabolic effect?

    Parabolic effect is not working at present when applets provide different lengths. Applets with large lengths decrease the animations speed and the applets with small lengths increase it. The best way for parabolic effect to work is for all applets to provide a squared layout that does not update its content positioning when zoomed. In order to make things easy for developers Latte can provide you with the best layout to achieve this without needing from you to make any calculations. To do this, you need to set it up as such:

    import QtQuick 2.0
    
    import org.kde.plasma.plasmoid 2.0
    
    Item {
        id: root
    
        Layout.minimumWidth: inLatte && isHorizontal  ? -1 : [plasma case]
        Layout.preferredWidth: inLatte && isHorizontal  ? -1 : [plasma case]
        Layout.maximumWidth: inLatte && isHorizontal  ? -1 : [plasma case]
    
        Layout.minimumHeight: inLatte && !isHorizontal  ? -1 : [plasma case]
        Layout.preferredHeight: inLatte && !isHorizontal  ? -1 : [plasma case]
        Layout.maximumHeight: inLatte && !isHorizontal  ? -1 : [plasma case]
    
        readonly property bool isHorizontal: plasmoid.formFactor === PlasmaCore.Types.Horizontal
    
        //! Latte Connection
        property QtObject LatteBridge: null
        readonly property bool inLatte: LatteBridge !== null
        //!
    }
    

    In the above example you can see that when the applet is not providing any information for its Layout [-1 case] then Latte has the freedom to set it in the best appropriate


    LatteBridge

    LatteBridge <properties>

    After the LatteBridge Object has been set from Latte you can access the following.

    latteBrige <properties>

    version[int] (readonly): LatteBridge Version whhich is based on Latte Version. For example, Latte 0.9.0 produces a unique integer that can be used for numeric comparisons for greater than, lower than etc. If you want to make a version comparison, you can try the following in your code. LatteBridge.version >= LatteBridge.actions.makeVersion(0,9,2)

    applyPalette [bool] (readonly) : true when latte is advising the applet to use the Latte colors palette in order to draw its contents with proper contrast

    inEditMode[bool] (readonly): true when Latte behaves as a Plasma Panel concerning external shadow rendering, transparency levels, etc.

    parabolicEffectEnabled[bool] (readonly): true when Latte Parabolid Effect is enabled.

    iconSize[int] (readonly): the current icon size used for all appletsin the containment this applet is present

    maxZoomFactor[real] (readonly): the current zoom factor with values from 1.0 to 2.0

    1 = No Scaling
    1.2 = Scale to 120%
    2 = Scale to 200%
    
    

    actions [QtObject] (readonly): you can use it to pass information to Latte concerning your applet requirements. This is explained in detail in the LatteBridge.actions section

    pallete [SchemeColors *QtObject] (readonly): the current Latte color scheme palette used. Properties available for color scheme object are provided through https://phabricator.kde.org/source/latte-dock/browse/master/app/wm/schemecolors.h

    windowsTracker [QtObject] (readonly): all windows tracking information that can be used from applets to update their contents. It is explained in detail in the LatteBridge.windowsTracker section. Important:You need to enable windowsTrackingEnabled first though LatteBridge.actions object.


    LatteBridge <signals>

    broadcasted(string action, variant value)

    Applets in Latte can create their own protocols in order to communicate with other applets. When such signal is received it means that some applet is requesting from you to make “action” with parameter “value” . A good example for this are the Window Title and Window AppMenu applets. These applets need to communicate with each other in order to hide or show themselves in Unity Mode. Window Title is shown when there is no mouse hovering and Window AppMenu when there is one. All this is orchestrated through applets without Latte taking any responsibility except broadcasting the requested actions only to the correct receivers. How applets are sending such actions through LatteBridge.actions is explained better at the relevant section. If you want to track this signal you can use:

    import QtQuick 2.0
    
    Item {
        id: root
    
        //! Latte Connection
        property QtObject LatteBridge: null
        readonly property bool inLatte: LatteBridge !== null
        //!
    
        Connections {
            target: LatteBridge
            onBroadcasted: {
                if (action === "actionname1") {
                    //! your code here
                } else if (action === "actionname2") {
                    //! your code here
                }
            }
        }
    
    }
    

    LatteBridge <actions>

    Through actions an applet can send information to Latte and other neighbour applets. The following functions can be used to accomplish this:

    setProperty(appletId, parameter, value)

    Applets can set their characteristics and demands through this function. For example when an applet wants to disable the Active Indicator in Latte Side can use:

    LatteBridge.actions.setProperty(plasmoid.id, “activeIndicatorEnabled”, false);

    OR when wants to disable the Latte Side Coloring that overlays the applets monochromatic in Smart Coloring mode then it can use:

    LatteBridge.actions.setProperty(plasmoid.id, “latteSideColoringEnabled”, false);

    getProperty(appletId, parameter)

    Applets can read the current assigned characteristics through this function:

    var indicatorEnabled = LatteBridge.actions.readProperty(plasmoid.id, “activeIndicatorEnabled”);

    broadcastToApplet(receiverPluginId, action, value)

    Applets can communicate with other neighbour applets. For example when Window Title is informing AppMenu that needs to hide itself it sends:

    LatteBridge.actions.broadcastToApplet(“ord.kde.windowappmenu”,”setVisible”, false);

    version(major, minor, patch)

    It is used to produce a unique integer based on major, minor and patch versions in order to compare different versions, for example:

    LatteBridge.version >= LatteBridge.actions.makeVersion(0,9,2)


    LatteBridge.actions <applet characteristics>

    Applets can have different demands and characteristics that can be set and accessed through setProperty and getProperty functions.

    activeIndicatorEnabled[bool]: false means Latte will not draw any indicator for this applet, a good example being the Global Menu plasmoid.

    latteIconOverlayEnabled[bool]: false means Latte will never try to identify the central icon used in order to make this applet draw itself correctly with parabolic effect. Most applets are using PlasmaCore.IconItem in order to draw the CompactRepresentation icon when they are in a panel, but plasma iconitem does not play nice with parabolic effect. This is why Latte is trying to handle the case and take resposibility by hiding the PlasmaCore.IconItem and draw a LatteComponents.IconItem instead. If you dont want this to happen then you must this property to false.

    latteSideColoringEnabled [bool]: false means Latte will never overlay any color over this applet because applet takes resposibility for painting itself at all cases.

    lengthMarginsEnabled [bool]: false means means Latte will not draw any margins around this applet comparing to its neighbours. Good example is the spacer plasmoid that in panel mode does not need any extra margins around it.

    means Latte will not draw any margins around this applet comparing to its neighbours. Good example is the spacer plasmoid that in panel mode does not need any extra margins around it.

    parabolicEffectLocked[bool]: true means Latte must disable parabolic effect for that specific applet.

    windowsTrackingEnabled[bool]: true means Latte must provide a, LatteBridge.windowsTracker object through LatteBridge


    LatteBridge.windowsTracker

    WindowTracker provides two major objects currentScreen and allScreens in order for applets to identify correctly which windows tracking states are useful for them.

    LatteBridge.windowsTracker.currentScreen <properties>

    activeWindowMaximized[bool] (readonly): true when there is an active and maximized windows in current session.

    activeWindowTouching[bool] (readonly) : true when there is an active window in current screen and that window is also touching the Latte dock/panel.

    existsWindowActive[bool] (readonly) : true when there is an active window in current screen.

    existsWindowMaximized[bool] (readonly): true when there is a maximized window in current screen independent of if this window is active or not.

    existsWindowTouching[bool] (readonly): true where there is a window in current screen that is touching the Latte dock/panel independent of if this window is active or not

    activeWindowScheme[SchemeColors *QtObject] (readonly): color scheme object for window that is touching Latte dock/panel in current screen and null if there is not any. Properties availble for color scheme object are provided through https://phabricator.kde.org/source/latte-dock/browse/master/app/wm/schemecolors.h

    lastActiveWindow[LastActiveWindow *QtObject] (readonly): last active window that is still present and shown in the current screen. Propertyies available for lastActiveWindow object are provided through https://phabricator.kde.org/source/latte-dock/browse/master/app/wm/tracker/lastactivewindow.h


    LatteBridge.windowTracker.allScreens <properties>

    activeWindowMaximized[bool] (readonly) : true when there is an active maximized window in any screen.

    existsWindowActive[bool] (readonly) : true when there is an active window in any screen.

    existsWindowMaximized[bool] (readonly) : true when there is a maximized window in any screen independent of if this window is active or not.

    activeWindowScheme[SchemeColors *QtObject] (readonly): color scheme object for active window in any screen, and null if there isn't any. Properties available for color scheme object are provided through https://phabricator.kde.org/source/latte-dock/browse/master/app/wm/schemecolors.h

    lastActiveWindow last active window that is still present and shown in any screen. Properties available for LastActiveWindow object are provided through https://phabricator.kde.org/source/latte-dock/browse/master/app/wm/tracker/lastactivewindow.h

    Applet Examples

    Latte Separator
    Latte Spacer
    Window Title Applet
    Window Buttons Applet
    Window AppMenu Applet


    Indicators

    Introduction

    In Latte v0.9 every indicator style has its own standalone qml implementation that can be found in its own package, just like Plasma qml-only applets. In that way every indicator style can support its own specific user settings and also abstract its implementation from the main Latte development. Online Indicators can be found at the kde store(https://store.kde.org/browse/cat/563/) and can be installed through Latte, Effects page without needing from the users any special actions to accomplish the task.

    Package Structure

    The Indicator package should have the following structure:

    metadata.desktop [required]
    package/ui/main.qml [required]
    package/config/main.xml [optional]
    package/config/config.qml [optional]
    

    Metadata.desktop

    Every indicator needs a desktop file in order to tell Latte where to find its implementation and what its author details are. The format is as such:

    [Desktop Entry]
    Name=Latte
    Comment=Latte default indicator
    
    Encoding=UTF-8
    Type=Service [required]
    Icon=latte-dock
    X-Plasma-API=declarativeappletscript [required]
    X-KDE-ServiceTypes=Latte/Indicator [required]
    
    X-Latte-MainScript=ui/main.qml [required]
    X-Latte-ConfigUi=config/config.qml [optional]
    X-Latte-ConfigXml=config/main.xml [optional]
    
    X-KDE-PluginInfo-Author=KDE Awesome Developer
    X-KDE-PluginInfo-Email=[email protected]
    X-KDE-PluginInfo-Name=org.kde.latte.default
    X-KDE-PluginInfo-Version=0.1
    X-KDE-PluginInfo-Category=Latte Indicator
    X-KDE-PluginInfo-License=GPL v2+
    X-KDE-PluginInfo-EnabledByDefault=true
    


    X-Plasma-API: must be present because it defines a qml-only plugin X-KDE-ServiceTypes: must be present with value Latte/Indicator otherwise the indicator can not be installed and loaded X-Latte-MainScript: must be present and defines the main qml file for the indicator implementation X-Latte-ConfigXml: defines the xml settings that are going to be used from indicator implementation and user settings. It is optional and a package may not include it X-Latte-ConfigUI: defines the qml settings user interface. It is provided only when the indicator has settings that the user can choose from in order to adjust the indicate apprearnace and behaviour

    QML Implementation

    package/ui/main.qml

    Every indicator main qml file must use LatteComponents.IndicatorItem at its root

    import QtQuick 2.0
    
    import org.kde.latte 0.2 as Latte
    import org.kde.latte.components 1.0 as LatteComponents
    LatteComponents.IndicatorItem {
        id: root
    
        providesFrontLayer: false
        providesHoveredAnimation: false
        ...
    
    }
    

    The LatteComponents.IndicatorItem provides options to inform Latte what requirements and capabilities this indicator provides in order to appear, function and behave properly. All IndicatorItem options are [optional]:

    LatteComponents.IndicatorItem [properties]

    needsIconColors [bool] : true when current icon main colors are needed. For example the Unity Indicator draws a background and glow that are provided from current icon colors.

    needsMouseEventCoordinates [bool]: true when mouse even coordinates are neded. An example is the click animation in android style that provides the Plasma Indicator.

    providerFrontLayer [bool] : true when a front layer is provided in order to draw contents above the current item/icon.

    providesHoveredAnimation [bool]: true if the Latte built-in hovered animation must be disabled

    provideClickAnimation [bool]: true if the Latte built-in clicked animation must be disabled

    extraMaskThickness [int]: How many pixels are needed above the indicator in order to be drawn correctly. Example: The Latte indicator in reverse mode can support glow, but that glow is drawn externally. Latte must be informed for this in order to not visually subtract that glow.

    minThicknessPadding [int]: The minimum thickness padding that is needd for the indicator

    minThicknessPadding: 0.2 //20% of current icon size
    

    svgImagePaths [Array (strings)]: Plasma::SVG files must be loaded from Latte in order to avoid high memory consumption

    svgImagePaths: [widgets/panel-background, ../icons/separator.svg]
    

    The first SVG icon is provided from current plasma theme, and the second is located relevant to the package/ui

    Tasks/Applets Information

    As long as IndicatorItem has been set for the main qml file then the entire indicator qml implementation gains two different objects ( level and indicator ) in order to access tasks/applets and general information

    <level> object [properties]

    <level>object [properties]

    isBackground [bool] (readonly) : true when the indicator background needs to be painted below the current icon/applet.

    isForeground [bool] (readonly) : true when the indicator foreground needs to be painted above the current icon/applet

    <level> object [signals]

    mousePressed(int x, int y, int button): can be tracked when needMouseEventSignals property has been enabled in IndicatorItem in order to get mouse x,y coordinates and which mouse button was released.

    < indicator > object [properties]

    isTask [bool] (readonly): true when main item is actually a task isApplet [bool] : true when main item is actually an applet

    isLauncher [bool] (readonly): true when main item is a task in launcher state isStartup [bool] (readonly): true when main item is a task in startup state isWindow [bool] (readonly): true when main item is a task in window state

    isActive [bool] (readonly): true when main item is active isGroup [bool] (readonly): true when main item is a group of tasks isHovered [bool] (readonly): true when main item is hovered isMinimized [bool] (readonly): true when main item is a task in minimized state isPressed [bool] (readonly): true when main item is pressed inAttention [bool] (readonly): true when main item requires attention inRemoving [bool] (readonly): true when main item in remove stage

    isSquare [bool] (readonly): true when main item is has a squared layout

    hasActive [bool] (readonly): true when a group of tasks has an active item hasMinimized [bool] (readonly): true when a group of tasks has at least one minimized window hasShown [bool] (readonly): true when a group of tasks has at least one shown (not minimimed) window

    windowsCount [int] (readonly): how many windows exist in a grouped tasks item windowsMinimizedCount [int] (readonly): how many minimized windows exist in a grouped tasks item

    currentIconSize [int] (readonly): current icon size used for the entire dock or panel maxIconSize [int] (readonly): maximum icon size that can occur from this dock or panel

    scaleFactor [int] (readonly): current icon size used for the entire dock or panel maxIconSize [int] (readonly): maximum icon size that can occur from this dock or panel

    scaleFactor [real] (readonly): current scale factor for this item with values from 1.0 to 2.0

    1 = Item is not zoomed
    1.2 = Items is zoomed by 20%
    2 = Item is zoomed by 100%
    

    panelOpacity [real] (readonly): current panel background opacity shadowColor [color] (readonly): current shadow color used for all items

    animationsEnabled [bool] (readonly): true when animations are enabled durationTime [real] (readonly): current duration time for animation. It is a multiplier that can be used for animations in order to respect user preference concerning animations speed

    usePlasmaTabsStyle [bool] (readonly): true when the user has disabled latte indicator drawing for applets

    iconBackgroundColor [color] (readonly):main background color produced from the current icon. [requires: needsIconColors:true from IndicatorItem]

    iconGlowColor [color] (readonly): main glow color produced from the current icon. [requires: needsIconColors:true from IndicatorItem]

    palette [QtObject] (readonly): current colors palette used. Provides backgroundColor, textColor etc. and [scheme] [string] (readonly) which is the absolutepath for the scheme file used indicator.palette.backgroundColor //like theme.backgroundColor

    configuration [QtObject] (readonly): object to access through indicator.configuration the user settings specified through main.xml file

    resources [QtObject] (readonly): object to access through indicator.resources indicator specified resources.

    resources.svgs [Array] (readonly): object to access through indicator.resources.svgs specified Plasma/Svgs from IndicatorItem.svgImagePaths

    import QtQuick 2.0
    import org.kde.plasma.core 2.0 as PlasmaCore
    import org.kde.latte 0.2 as Latte
    import org.kde.latte.components 1.0 as LatteComponents
    LatteComponents.IndicatorItem {
        id: root
    
        svgImagePaths: [widgets/panel-background, ../icons/separator.svg]
        ...
           PlasmaCore.SvgItem {
                 id: panelBackgroundSvgItem
    
            svg: indicator.resources.svgs[0]
       }
       ...
    }