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Please review the following information to ensure ** the GNU Free Documentation License version 1.3 requirements ** will be met: https://www.gnu.org/licenses/fdl-1.3.html. ** ****************************************************************************/ /*! \example loginui4 \ingroup studioexamples \ingroup gstutorials \title Log In UI - Part 4 \brief Illustrates how to use the timeline and states to animate UI components. \previouspage {Log In UI - Part 3} \image loginui4.gif "Log In UI" \e{Log In UI - Part 4} is the fourth in a series of examples that build on each other to illustrate how to use \QDS to create a simple UI with some basic UI components, such as pages, buttons, and entry fields. Part 4 describes how to use the timeline and states to animate UI components. In Part 3, you learned how to use states to simulate page changes in a UI and connections to provide user interaction with it. In Part 4, you will now learn another way of animating the UI by using timeline animations that you bind to states. These instructions build on: \list \li \l {Log In UI - Part 1} \li \l {Log In UI - Part 2} \li \l {Log In UI - Part 3} \endlist The \e {Learn Qt Quick} sections provide additional information about the features of QML and Qt Quick that are relevant to the task at hand. \section1 Animating UI Components In Part 3, you changed the visibility property in different states to simulate changing pages. To make sure that those changes won't interfere with the changes to the opacity property you will make in Part 4, you will first remove the states. Then, you will add a timeline and insert keyframes for the opacity property to hide the password verification field and back button on the login page and the login button on the registration page. Because we want the password verification field to appear to slide down from the password field, you will also need to insert a keyframe for its anchor margin property. To be able to animate the anchor, you also need to pull out the fields from the fields column and anchor them to the page and to each other instead. To preview the changes that you make to the UI while you make them, select the \inlineimage live_preview.png (\uicontrol {Show Live Preview}) button on the \uicontrol {Form Editor} toolbar or press \key {Alt+P}. \section2 Replacing Columns with Anchors First, you will prepare the page for adding animation: \list 1 \li Open \e {Screen01.ui.qml} in \uicontrol {Form Editor} for editing. \li In the \uicontrol States view, select the \inlineimage close.png (\uicontrol Close) button in \e loginState and \e registerState to remove the states. \li Select the fields in \e fieldColumn in \uicontrol Navigator and drag and drop them to \e loginPage. \li Select \e fieldColumn in \uicontrol Navigator and press \key Delete to delete it. \li Select \e usernameField in \uicontrol Navigator. \li In \uicontrol Properties > \uicontrol Layout, select the \inlineimage anchor-top.png (\uicontrol Top) button to anchor the top of the field to the top of its parent (\e loginPage). \QDS will suggest an appropriate margin based on the current Y-position of the field. \li Select the \inlineimage anchor-horizontal-center.png (\uicontrol {Horizontal Center}) button to anchor the horizontal center of the field to that of its parent. \li Select \e passwordField, and then select the \uicontrol Top button in \uicontrol Properties > \uicontrol Layout. \li In the \uicontrol Target field, select \e usernameField to anchor the top of \e passwordField to the bottom of \e usernameField with a 5-pixel margin. \li Select the \uicontrol {Horizontal Center} button to anchor the horizontal center of \e passwordField to that of \e usernameField. \li Repeat the above steps to anchor the top of \e verifyPasswordField to the bottom of \e passwordField with a 5-pixel margin and to anchor its horizontal center to that of \e passwordField. \li Select \uicontrol File > \uicontrol Save or press \key {Ctrl+S} to save your changes. \endlist You could also animate the Y-position property of the verify password field for a similar effect. In that case, you would need to use absolute positioning for the field. This is less flexible if you export your design from a design tool, such as Adobe Photoshop, and decide to change your design and export it again at some point. In that case, the margins would probably stay the same, even if the positions of the fields on the page would change. Your page now should look something like this in the Design mode and live preview: \image loginui4-page.png "UI with all the buttons and fields in the Design mode" \section2 Adding a Timeline and Animation Settings You are now ready to add the \l{Creating Animations}{timeline}. You will need two animations, one for moving into the registration page and another for returning to the login page. You can use the same animation for both cases, by running it either from the beginning to the end or from the end to the beginning. To add a timeline with settings for running the animation: \list 1 \li Select \uicontrol View > \uicontrol Views > \uicontrol Timeline to open the \uicontrol Timeline view. \li In \uicontrol Timeline, select \inlineimage plus.png to add a 1000-frame timeline and settings for running the animation. \image loginui4-timeline-settings.png \li In the \uicontrol {Animation ID} field, enter \e toLoginState. \li Deselect the \uicontrol {Running in base state} check box, because you want the animation to run only after the user clicks the \uicontrol {Create Account} button. You can use the default settings for the other fields. \li Select \inlineimage plus.png next to the \uicontrol {Animation Settings} group to add settings for running the animation when the user clicks the back button. \li In the \uicontrol {Animation ID} field, enter \e toRegisterState. \li To run the animation backwards when the user clicks the back button, enter \e 1000 in the \uicontrol {Start frame} field and \e 0 in the \uicontrol {End frame} field. \li Select \uicontrol Close in the \uicontrol {Timeline Settings} view to save the timeline and the animation settings. \endlist Next, you will record the animation in \uicontrol Timeline. \section2 Inserting Keyframes You will now insert keyframes and record property changes in \uicontrol Timeline: \list 1 \li Select \e backButton in \uicontrol Navigator. \li In \uicontrol Properties > \uicontrol Opacity > \uicontrol Settings, select \uicontrol {Insert Keyframe} to insert a keyframe for the opacity property of the button. \li Check that the playhead is in frame 0, and select the \inlineimage recordfill.png (Per Property Recording) button for the \uicontrol opacity property of \e backButton to start recording property changes. \image loginui4-timeline-opacity.png "Record button for the opacity property" \li In the field next to the opacity property name on that same line, type 0 to hide the button, and press \key Enter to save the value. \li Move the playhead to frame 1000 and change the opacity value to 1 to show the button. \li Select the record button again to stop recording property changes. If you forget this, all the following changes will be recorded, and the results will be unpredictable. \li Select \e verifyPasswordField in \uicontrol Navigator, and repeat the above steps to insert a keyframe for the \uicontrol opacity property of the field and to record changes for it. \li Select \e loginButton in \uicontrol Navigator, and repeat the above steps to insert a keyframe for the \uicontrol opacity property of the button and to record changes for it. However, this time the opacity value needs to be 1 in frame 0 and 0 in frame 1000. \li Select \uicontrol File > \uicontrol Save or press \key {Ctrl+S} to save your changes. \endlist When you move the playhead along the timeline, you can see how the login button fades out while the verify password field and back button fade in. You will now animate the top anchor margin of the verify password field to make it appear to slide down from the password field. \section2 Animating Anchors To animate the top anchor margin of the verify password field: \list 1 \li Select \e verifyPasswordField in \uicontrol Navigator. \li Select \uicontrol Properties > \uicontrol Layout > \uicontrol Margin > \uicontrol {Insert Keyframe} to insert a keyframe for the top anchor margin of \e verifyPasswordField. \li In \uicontrol Timeline, check that the playhead is in frame 0, and select the record button for the \e anchors.topMargin property of \e verifyPasswordField. \li In the field next to the property, set a negative value for the top anchor margin, -40, to place \e verifyPasswordField on top of \e passwordField. \li Move the playhead to frame 1000 and change the top anchor margin to 5, so that \e verifyPasswordField appears to slide down and settle below \e passwordField. \li Select the record button again to stop recording property changes. \li Select \uicontrol File > \uicontrol Save or press \key {Ctrl+S} to save your changes. \endlist \section2 Adding Easing Curves You will now add an \l{Editing Easing Curves}{easing curve} to the anchor margin animation that will make the transition seem smoother: \list 1 \li Click the keyframe marker \inlineimage keyframe_linear_inactive.png for the \e anchors.topMargin property at frame 1000 on the timeline to select it. \li Right-click the keyframe marker to open a context menu, and select \uicontrol {Edit Easing Curve} to add an easing curve to the animation. \li In \uicontrol {Easing Curve Editor}, select \e easeOutSine. \image loginui4-easing-curve.png \li Select \uicontrol OK to close the editor. \endlist When you attach easing curves to keyframes, the shape of the keyframe marker changes from \inlineimage keyframe_linear_inactive.png to \inlineimage keyframe_manualbezier_inactive.png . Your timeline should now look something like this: \image loginui4-timeline.png "Timeline view with the recorded property changes" Next, you create states for the login and registration pages and bind them to the animation settings. \section1 Binding Animation to States You will now bring back the \l{Adding States}{states} in the \uicontrol States view and bind them to the animation settings in \uicontrol Timeline: \list 1 \li In \uicontrol States, select \uicontrol {Create New State} twice to add two states called \e loginState and \e registerState. You don't need to make any property changes this time, because you'll bind the states to property animations. \li In \uicontrol Timeline, select the \inlineimage animation.png (\uicontrol {Timeline Settings (S)}) button on the toolbar (or press \key S to open the \uicontrol {Timeline Settings} dialog. \image loginui4-timeline-settings-states.png \li Double-click the cell in the \uicontrol Timeline column on the \e loginState row, and select \e timeline in the list. \li Double-click the cell in the \uicontrol Animation column on the \e loginState row, and select \e toRegisterState. \li Repeat these steps for \e registerState row, but select \e toLoginState in the \uicontrol Animation column. \li Click \uicontrol Close to save the timeline settings. \endlist In the live preview, you can now click the \uicontrol {Create Account} button to go to the registration page and the back button to return to the login page. \image loginui4.gif "Moving between login page and registration page" \section2 Learn Qt Quick - Timeline The Qt Quick Timeline module provides QML types to use timelines and keyframes to animate component properties in UIs. Animating properties enables their values to move through intermediate values instead of immediately changing to the target value. The Keyframe type specifies the value of a keyframe on a timeline. \QDS automatically adds keyframes between two keyframes, and sets their values evenly to create an appearance of movement or transformation. An easing curve can be attached to the keyframe to change the appearance of the animation. For more information about easing curve types, see the documentation for \l [QML] {PropertyAnimation}{easing curves}. To be able to use the functionality of Qt Quick Timeline types, \QDS adds the following \e import statement to the QML files where it uses the types: \quotefromfile loginui4/Screen01.ui.qml \skipto QtQuick.Timeline \printuntil 1.0 All the properties and functions of the QML types from this module are available in the Design mode, and therefore it is enough to learn how to use \uicontrol Timeline, as described in \l {Creating Animations}. \section1 Next Steps For more examples about using timelines, see \l{Examples and Tutorials}. To watch a video tutorial about creating timelines and adding keyframes, select \e {Learn to use Qt Design Studio Part 2} in the \uicontrol Tutorials tab in the \uicontrol Welcome mode. */