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QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
Graphics
Gestures Library Reference
The Gestures library provides gesture recognizers to detect gestures through touch events that occur when you place one or more fingers on a touch screen.
Gestures Library Reference
The Gestures library primarily provides gesture recognizers to detect gestures through mtouch events that occur when you place one or more fingers on a touch screen.
pinch.h
Definition of the pinch gesture.
pinch_gesture_alloc()
Allocate and initialize the pinch gesture structure

QNX Momentics IDE User's Guide
This User's Guide describes version 8.0 of the Integrated Development Environment (IDE) that's part of the QNX Tool Suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
- Quickstart Guide
- System Architecture
  The System Architecture guide accompanies the QNX OS and is intended for both application developers and end-users.
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  - Gestures Library Reference
    The Gestures library provides gesture recognizers to detect gestures through touch events that occur when you place one or more fingers on a touch screen.
    - Gestures Library Overview
      The Gestures library provides gesture recognizers to detect gestures through touch events that occur when you place one or more fingers on a touch screen.
    - Gesture Recognition
      Gesture recognition is performed by gesture recognizers that detect gestures through touch events.
    - Custom Gestures
      You can define gesture recognizers to detect gestures that are not already supported by the Gestures library (custom gestures). Gesture recognizers that are used to detect custom gestures can be compiled with the application code and added to a gesture set in the same way that system gesture recognizers are added to a gesture set.
    - Gesture Tutorials
      Gestures tutorials aim to help you understand how to use the Gestures library in your own applications by providing step-by-step guides.
    - Gestures Library Reference
      The Gestures library primarily provides gesture recognizers to detect gestures through mtouch events that occur when you place one or more fingers on a touch screen.
      - bucket.h
        Data types and functions for gesture buckets.
      - defaults.h
        Global settings for gesture timings.
      - double_tap.h
        Definition of the double tap gesture.
      - event_list.h
        Data types and functions for event lists.
      - long_press.h
        Definition of the long press gesture.
      - pinch.h
        Definition of the pinch gesture.
        gesture_pinch_t
        The pinch gesture data type
        pinch_gesture_alloc()
        Allocate and initialize the pinch gesture structure
        pinch_gesture_default_params()
        Initialize the pinch parameters
        pinch_params_t
        Pinch gesture parameters.
      - press_and_tap.h
        Definition of the press and tap gesture.
      - rotate.h
        Definition of the rotate gesture.
      - set.h
        Data types and functions for gesture sets.
      - swipe.h
        Definition of the swipe gesture.
      - tap.h
        Definition of the tap gesture.
      - timer.h
        Functions and datatypes for gestures timers.
      - triple_tap.h
        Definition of the triple tap gesture.
      - two_finger_pan.h
        Definition of the two finger pan gesture.
      - two_finger_tap.h
        Definition of the two finger tap gesture.
      - two_finger_double_tap.h
        Definition of the double tap gesture.
      - types.h
        Common data types and helper functions.
  - Image Library Reference
  - Input Events Library Reference
    The Input Events library provides the framework necessary for Screen Graphics Subsystem to communicate with your touch driver.
  - OpenWF Configuration Developer's Guide
    If you are integrating a new display, you must configure and provide the parameters of your display based on its specifications via the OpenWF Display Configuration API (Wfdcfg Library).
  - OpenWF Display Server User's Guide
    The OpenWF Display Server (wfd-server) is a resource manager that provides applications the ability to show image buffers directly to the display controller via the OpenWF Display API.
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    QNX Screen Graphics Subsystem is a graphics framework that provides all the functionality necessary to develop interactive user experiences.
  - Video Capture Developer's Guide
    The video capture framework provides applications the ability to capture frames from a video input source. These frames can be passed to a graphics component such as Screen for display.
- Programming
- System Security Guide
  The QNX System Security Guide is intended for both system integrators who are responsible for the security of a QNX OS system and developers who want to create a QNX OS resource manager free from vulnerabilities.
- Utilities & Libraries
- Migrating to QNX OS 8.0
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX OS in the Amazon cloud environment.
QNX Toolkit for Visual Studio Code
This User's Guide describes the QNX^® Toolkit for Visual Studio Code. The guide introduces you to the QNX Toolkit by explaining the QNX development environment and how to build, run, and debug your QNX^® Operating System (OS) applications and systems.
QNX Hypervisor User's Guide
This User's Guide explains the QNX hypervisor architecture and provides instructions for installing and running a QNX Hypervisor system, changing system components and configuration, and using hypervisor features such as virtual devices (vdevs).
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation, explains how to obtain technical support, and provides some information about licensing.

pinch_gesture_alloc()

QNX SDP8.0Gestures Library ReferenceAPIDeveloperProgramming

Allocate and initialize the pinch gesture structure

Synopsis:

#include <gestures/pinch.h>

gesture_pinch_t* pinch_gesture_alloc(pinch_params_t *params,
                                     gesture_callback_f callback,
                                     struct gestures_set *set)

Arguments:

params: A pointer to the pinch gesture parameters.
callback: The function to invoke when the pinch gesture changes state.
set: A pointer to the gesture set to add this pinch gesture to.

Library:

libgestures

Description:

This function allocates a new pinch gesture data structure, initializes it with the specified parameters and callback function, and adds it to the specified gesture set.

Returns:

A pointer to an initialized pinch gesture.

Page updated: March 05, 2025